Re: Issuer Warrant Transaction

Trade Date:

April 20, 2009

Warrants:

Equity call warrants, each giving the holder the right to purchase one Share at the Strike Price, subject to the Settlement Terms set forth below. For the purposes of the Equity Definitions, each reference to a Warrant herein shall be deemed to be a reference to a Call Option.

Warrant Style:

American

Buyer:

Bank

Seller:

The Company

Shares:

The Class A common stock of Company, par value USD 0.01 per Share (Exchange symbol “ SBAC ”)

Number of Warrants:

[ Barclays Bank PLC – 6,665,571; Citibank, N.A. - 4,443,714; Deutsche Bank AG London – 1,851,548; JPMorgan Chase Bank, National Association – 1,110,929; Wachovia Capital Markets LLC – 740,619] subject to adjustments provided herein

Daily Number of Warrants:

For any Expiration Date, as provided in Schedule A to this Confirmation, subject to adjustment pursuant to the provisos to “Expiration Date(s)”; provided that upon the exercise of any Warrants on a date preceding the first Expiration Date, the Daily Number of Warrants for each Expiration Date (other than the final Expiration Date) shall be reduced by a number of Warrants equal to the quotient obtained by dividing the total number of Warrants so exercised by 60 (rounded down to the nearest whole number) (such quotient, the “ Daily Reduction Amount ”) and the Daily Number of Warrants for the final Expiration Date shall be reduced by a number of Warrants equal to the excess of the total number of Warrants so exercised over the sum of the Daily Reduction Amount for all preceding Expiration Dates.

Warrant Entitlement:

One Share per Warrant

Number of Shares:

The product of the Number of Warrants and the Warrant Entitlement.

Multiple Exercise:

Applicable

Minimum Number of Warrants:

1

Maximum Number of Warrants:

All Warrants remaining unexercised as of the remaining Exercise Date(s).

Integral Multiple:

1

Strike Price:

USD 44.6400

Premium:

[Barclays Bank PLC - USD 40,178,025.00; Citibank, N.A. - USD 26,785,350.00; Deutsche Bank AG London – USD 10,839,375.00; JPMorgan Chase Bank, National Association – USD 6,503,625.00; Wachovia Capital Markets LLC – USD 4,335,750.00]

Premium Payment Date:

April 24, 2009

Exchange:

The NASDAQ Global Select Market

Related Exchange(s):

The principal exchange(s) for options contracts or futures contracts, if any, with respect to the Shares.

Expiration Time:

The Valuation Time

Expiration Date(s):

Each Exchange Business Day during the period from and including the First Expiration Date to and including the 60 ^th Exchange Business Day following the First Expiration Date shall be an “Expiration Date” for a number of Warrants equal to the Daily Number of Warrants on such date; provided that, notwithstanding the foregoing and anything to the contrary in the Equity Definitions, if a Market Disruption Event occurs on any Expiration Date (including the First Expiration Date), the Calculation Agent shall make adjustments, if applicable, to the Daily Number of Warrants or shall reduce such Daily Number of Warrants to zero for which such day shall be an Expiration Date and shall designate an Exchange Business Day or a number of Exchange Business Days as the Expiration Date(s) for the remaining Daily Number of Warrants or a portion thereof for the originally scheduled Expiration Date; and provided further that if such Expiration Date has not

occurred pursuant to this clause as of the eighth Exchange Business Day following the last scheduled Expiration Date under the Transaction, the Calculation Agent shall have the right to declare such Exchange Business Day to be the final Expiration Date and the Calculation Agent shall determine its good faith estimate of the fair market value for the Shares as of the Valuation Time on that eighth Exchange Business Day or on any subsequent Exchange Business Day, as the Calculation Agent shall determine using commercially reasonable means.

First Expiration Date:

January 2, 2015, subject to Market Disruption Event below.

Consequences of a Disrupted Day:

Notwithstanding the foregoing and anything to the contrary in the Equity Definitions and not limiting anything set forth under “Expiration Date(s)” above, if any Exercise Date occurring prior to the First Expiration Date is a Disrupted Day, the Calculation Agent may reduce the number of Warrants (including reducing the number to zero) for which such day shall be an Exercise Date.

Automatic Exercise:

Applicable; and means that, unless all Warrants have been previously exercised hereunder, a number of Warrants for each Expiration Date equal to the Daily Number of Warrants (as adjusted pursuant to the terms hereof) for such Expiration Date will be deemed to be automatically exercised.

Market Disruption Event:

Section 4.3(a)(ii) is hereby amended by adding after the words “or Share Basket Transaction” in the first line thereof a phrase “a failure by the Exchange or Related Exchange to open for trading during its regular trading session or” and replacing the phrase “during the one-half hour period that ends at the relevant Valuation Time” with the phrase “at any time during the regular trading session on the Exchange or any Related Exchange, without regard to after hours or any other trading outside of the regular trading session hours”.

Valuation Time:

At the close of trading of the regular trading session on the Exchange; provided that if the principal trading session is extended, the Calculation Agent shall determine the Valuation Time in its reasonable discretion.

Valuation Date:

Each Exercise Date. Notwithstanding anything to the contrary in the Equity Definitions, if there is a Market Disruption Event on any Valuation Date, then the Calculation Agent shall determine the Settlement Price for such Valuation Date on the basis of its good faith estimate of the market value for the relevant Shares on such Valuation Date.

Method of Settlement:

Net Share Settlement; provided that, with respect to any Warrants exercised on the Expiration Dates (and only such Warrants), Cash Settlement shall apply if the Company validly elects Cash Settlement pursuant to the provisions of “Cash Settlement Election” below.

Net Share Settlement:

On the relevant Settlement Date, Company shall deliver to Bank, the Share Delivery Quantity of Shares for such Settlement Date to the account specified hereto free of payment through the Clearance System.

Share Delivery Quantity:

For any Settlement Date, a number of Shares, as calculated by the Calculation Agent, equal to the Net Share Settlement Amount for such Settlement Date divided by the Settlement Price on the Valuation Date in respect of such Settlement Date rounded down to the nearest whole number, plus cash in lieu of any fractional Shares (based on such Settlement Price).

Net Share Settlement Amount:

For any Settlement Date, an amount equal to the product of (i) the Number of Warrants exercised or deemed exercised on the relevant Exercise Date (or in the case of any exercise (including any Automatic Exercise) on an Expiration Date, the Daily Number of Warrants for such Expiration Date), (ii) the Strike Price Differential for such Settlement Date and (iii) the Warrant Entitlement. For avoidance of doubt, if any Warrants are exercised prior to the first Expiration Date, the Calculation Agent will proportionately adjust each Daily Number of Warrants to reflect such exercise.

Strike Price Differential:

(a) If the Settlement Price for any Valuation Date is greater than the Strike Price, an amount equal to the excess of such Settlement Price over the Strike Price; or

(b) If such Settlement Price is less than or equal to the Strike Price, zero.

Settlement Price:

For any Valuation Date, the per Share volume-weighted average price for such Valuation Date as displayed under the heading “Bloomberg VWAP” on Bloomberg page SBAC.UQ <equity> AQR (or any successor thereto) in respect of the period from 9:30 a.m. to 4:00 p.m. (New York City time) on such Valuation Date or if such price is unavailable, the market value of one Share on such Valuation Date, as determined by the Calculation Agent in its reasonable discretion (in each case, without regard to pre-open or after hours trading outside of any regular trading session for such Valuation Date). Notwithstanding anything to the contrary in the Equity Definitions, if there is a Market Disruption Event on any Valuation Date, then the Calculation Agent shall determine the Settlement Price for such Valuation Date on the basis of its good faith estimate of the market value for the relevant Shares on such Valuation Date.

Settlement Date:

For any Exercise Date, the date defined as such in Section 6.2 of the Equity Definitions, subject to Section 9(p)(i) hereof.

Cash Settlement Election:

With respect to all Warrants to be exercised on the Expiration Dates, the Company can elect Cash Settlement by delivering a written notice to Bank (the “ Cash Settlement Notice ”) on or prior to the fifth (5 ^th ) scheduled Exchange Business Day immediately preceding the First Expiration Date, which Cash Settlement Notice shall contain:

(i) a representation that (x) on the date of such Cash Settlement Notice, neither the Company nor any of its affiliates is in possession of any material non-public information with respect to the Company or its Shares, (y) the Company is electing Cash Settlement in good faith and not as part of a plan or scheme to evade the prohibitions of Rule 10b-5 under the Securities Exchange Act of 1934, as amended (the “Exchange Act ”) and (z) the Company has not entered into or altered any hedging transaction relating to the Shares corresponding to or offsetting the Transaction;

(ii) a representation that the Company is not electing Cash Settlement to create actual or apparent trading activity in the Shares (or any security convertible into or exchangeable for the Shares) or to raise or depress or otherwise manipulate the price of the Shares (or any security convertible into or exchangeable for the Shares);

(iii) an acknowledgment by the Company that (A) any transaction by Bank following the Company’s election of Cash Settlement shall be made at Bank’s sole discretion and for Bank’s own account and (B) the Company does not have, and shall not attempt to exercise, any influence over how, when, whether or at what price to effect such transactions, including, without limitation, the price paid or received per Share pursuant to such transactions, or whether such transactions are made on any securities exchange or privately; and

(iv) an agreement by the Company that, during the period commencing on the date of such Cash Settlement Notice and ending on the second Exchange Business Day following the last Settlement Date hereunder, without the prior written consent of Bank, the Company shall not, and shall cause its affiliates and affiliated purchasers (each as defined in Rule 10b-18 under the Exchange Act) not to, directly or indirectly (including, without limitation, by means of a derivative instrument), purchase, offer to purchase, place any bid or limit order that would effect a purchase of, or commence any tender offer relating to, any Shares or any security convertible into or exchangeable for the Shares in the public markets.

Cash Settlement:

If Cash Settlement is applicable, on each Settlement Date, the Company shall deliver to Bank (to an account specified by Bank) the Net Share Settlement Amount for such Settlement Date.

In addition to any other requirements set forth herein, the Company agrees that it shall not have the right to elect Cash Settlement if Bank notifies the Company that, in the reasonable judgment of Bank the election of Cash Settlement or any purchases of Shares that Bank (or its affiliates) might make in connection therewith based upon the advice of counsel and as a result of events occurring after the Trade Date, would raise material risks under applicable securities laws.

Failure to Deliver:

Inapplicable

Other Applicable Provisions:

The provisions of Sections 6.6, 6.7, 6.8, 6.9 and 6.10 of the Equity Definitions will be applicable, except that all references in such provisions to “Physically-Settled” shall be read as references to “Net Share Settled”. “Net Share Settled” in relation to any Warrant means that Net Share Settlement is applicable to that Warrant.

Adjustments applicable to the Warrants:

Method of Adjustment:

Calculation Agent Adjustment. For the avoidance of doubt, in making any adjustments under the Equity Definitions, the Calculation Agent may adjust the Strike Price, the Number of Warrants, the Daily Number of Warrants and the Warrant Entitlement. Notwithstanding the foregoing, any cash dividends or distributions on the Shares, whether or not extraordinary, shall be governed by Section 9(k) of this Confirmation and not by Section 9.1(c) of the Equity Definitions.

Extraordinary Events applicable to the Transaction:

Consequence of Merger Events

(a) Share-for-Share:

Alternative Obligation; provided that the Calculation Agent will determine if the Merger Event affects the theoretical value of the Transaction and if so Bank in its sole discretion may elect to make adjustments to any of the Strike Price, the Number of Warrants, the Daily Number of Warrants, the Warrant Entitlement and any other term necessary to reflect the characteristics (including volatility, dividend practice, borrow cost and liquidity) of the New Shares. Notwithstanding the foregoing, Cancellation and Payment shall apply in the event the New Shares are not publicly traded on a United States national securities exchange or quoted on The NASDAQ Global Select Market or The NASDAQ Global Market (or their respective successors).

Share-for-Other:

Cancellation and Payment

(c) Share-for-Combined:

Cancellation and Payment; provided that on or prior to the Merger Date the Bank may elect, in its sole discretion, to apply the consequence specified opposite “Share for Share” to that portion of the consideration that consists of New Shares (as determined by the Calculation Agent) and the consequence specified opposite “Share for-Other” to that portion of the consideration that consists of Other Consideration (as determined by the Calculation Agent).

(a) Share-for-Share:

Modified Calculation Agent Adjustment (as defined in the 2002 Definitions and including any relevant cross references)

(b) Share-for-Other:

Modified Calculation Agent Adjustment (as defined in the 2002 Definitions and including any relevant cross references)

(c) Share-for-Combined:

Modified Calculation Agent Adjustment (as defined in the 2002 Definitions and including any relevant cross references)

Nationalization or Insolvency:

Cancellation and Payment

4. Calculation Agent:

Bank, acting in its capacity as Calculation Agent