THIRD AMENDMENT TO LEASE AGREEMENT

EXHIBIT 10.16

THIRD AMENDMENT TO LEASE AGREEMENT

     THIS THIRD AMENDMENT TO LEASE AGREEMENT (the “Third Amendment”), is made this 3 ^rd day of June, 2008, by 3280 PEACHTREE I LLC (as “Landlord”) and AMERICAN TELECONFERENCING SERVICES, LTD. D/B/A PREMIERE GLOBAL SERVICES (as “Tenant”).

W I T N E S S E T H:

     WHEREAS, Landlord and Tenant did enter into that certain Lease Agreement, dated as of October 28, 2005 (the “Original Lease”), for space (consisting of all of the 9 ^th floor, containing 23,684 square feet of Rentable Floor Area) in that certain building located at 3280 Peachtree Road, Atlanta, Georgia (the “Building”), as such space is more particularly described in the Original Lease (the “Demised Premises”).

     WHEREAS, Landlord and Tenant did enter into that certain First Amendment to Lease Agreement, dated as of July 31, 2006 (the “First Amendment”).

     WHEREAS, Landlord and Tenant did enter into that certain Second Amendment to Lease Agreement, dated as of March 15, 2007 (the “Second Amendment”).

     WHEREAS, the Original Lease, as modified by the First Amendment and Second Amendment, is herein collectively referred to as the Lease.

     WHEREAS, Landlord and Tenant desire to modify and amend the Lease, in the manner and for the purposes herein set forth.

     NOW, THEREFOR, for and in consideration of the mutual premises, and for Ten and No/100 Dollars ($10.00) and other good and valuable consideration, paid by the parties hereto to one another, the receipt and sufficiency of which are acknowledged by the parties hereto, the parties hereto hereby covenant and agree as follows:

     1. Defined Terms . All capitalized terms not defined herein shall have the same meaning as set forth in the Lease.

     2. Increase in Size of Demised Premises . Landlord hereby leases and rents to Tenant and Tenant hereby leases and rents from Landlord, an additional 7,818 square feet of Rentable Floor Area on the eighth (8 ^th ) floor of the Building (the “8 ^th Floor Expansion Space”), known as “Suite 820”, as shown on Exhibit “A” , attached hereto and by this reference incorporated herein. The square feet of Rentable Floor Area of the Demised Premises, which was 23,684 square feet of Rentable Floor Area, shall be, from and after the “8 ^th Floor Commencement Date” (as that term is herein defined), 31,502 square feet of Rentable Floor Area. The 8 ^th Floor Expansion Space shall be

and be deemed to be a part of the Demised Premises leased under the Lease, on the terms set forth therein, except to the extent of the specific terms as set forth in this Third Amendment.

     3. Base Rental Due from Tenant . (a) Base Rental shall be due from Tenant, and Tenant hereby covenants and agrees to pay Base Rental, as follows:

          (a) For the 8 ^th Floor Expansion Space, containing 7,818 square feet of Rentable Floor Area  

          (b) For the original Demised Premises, containing 23,684 square feet of Rentable Floor Area

          (c) So long as no Event of Default then exists, no Base Rental shall be due from Tenant for the 8 ^th Floor Expansion Space, for the first three (3) months after the 8 ^th Floor Commencement Date.

     4. Additional Rental . Tenant’s Additional Rental and Tenant’s Forecast Additional Rental shall be charged to and be due and payable from Tenant with respect to the 8 ^th Floor Expansion Space and the Demised Premises leased under the Lease, for the Term Addition, on the same terms and conditions as is set forth in the Lease.

     5. Tenant Improvement Allowance and Other Improvements . (a) Landlord shall provide to Tenant an allowance for the 8th Floor Expansion Space of Forty-Five and No/100 Dollars ($45.00) per square foot of Rentable Floor Area therein, or $351,810.00 in the aggregate (the “8 ^th Floor Expansion Space Allowance”). The 8 ^th Floor Expansion Space shall be delivered to Tenant in its “as is, where is” condition (except that Landlord shall cause such space to be in compliance with any applicable laws, codes, regulations and ordinances and shall cause any electrical, life safety, plumbing, heating, ventilation and cooling systems serving the 8 ^th Floor Expansion Space to be in good working order), in lieu of the condition set forth in the work letter attached as Exhibit “D” to the Original Lease (the “Original Work Letter”). Tenant’s build out of and improvements of the 8 ^th Floor Expansion Space shall be performed in accordance with and subject to the terms of the Original Work Letter. The 8 ^th Floor Expansion Space Allowance shall be paid to Tenant within thirty (30) days after Tenant has presented to Landlord reasonable evidence of (a) any hard or soft costs incurred by Tenant and relating to improvements or alterations made or being made to the Demised Premises (including, but not limited to, the 8 ^th Floor Expansion Space or any other portion of the Demised Premises in the Building), including, but not limited to, any such costs incurred prior to the date of this Third Amendment, or (b) any hard or soft costs incurred by Xpedite Systems, LLC, with respect to any Building space leased by Xpedite Systems, LLC, including but not limited to, any such costs incurred prior to the date of this Third Amendment, or (c) any costs incurred by Tenant or Xpedite Systems, LLC, for wiring or telecommunications installation, or (d) any costs incurred by Tenant for furniture for the 8 ^th Floor Expansion Space (but, with respect to this item (d), no more than $70,362.00 may be allocated to and used for furniture in the 8 ^th Floor Expansion Space). Tenant shall have the right to require payments of the 8 ^th Floor Expansion Space Allowance on a monthly basis.

          (b) Landlord shall also provide an additional allowance of $236,840 for work performed or to be performed by Tenant on the original Demised Premises (the “Additional Allowance”). The Additional Allowance shall be paid to Tenant within thirty (30) days after Tenant has presented to Landlord reasonable evidence of (a) any hard or soft costs incurred by Tenant and relating to improvements or alterations made or being made to the Demised Premises (including, but not limited to, the 8 ^th Floor Expansion Space or any other portion of the Demised Premises in the Building), including, but not limited to, any such costs incurred prior to the date of this Third Amendment, or (b) any hard or soft costs incurred by Xpedite Systems, LLC, with respect to any Building space leased by Xpedite Systems, LLC, including but not limited to, any such costs incurred prior to the date of this Third Amendment, or (c) any costs incurred by Tenant or Xpedite Systems, LLC, for wiring or telecommunications installation, or (d) any costs incurred by Tenant for furniture for the 8 ^th Floor Expansion Space (but, with respect to this item (d), no more than $47,368.00 may be allocated to and used for furniture in the 8 ^th Floor Expansion Space). Tenant shall have the right to require payments of the Additional Allowance on a monthly basis.

          (c) Tenant shall, at Tenant’s sole cost and expense, run such lines and pipes as are required so that Tenant can install, subject to and as limited by applicable law, at Tenant’s sole cost, a washer and dryer, in a location within the Demised Premises to be provided by Tenant, but the location and methods of installation of lines and pipes and the washer and dryer shall be subject to Landlord’s reasonable consent, and shall otherwise subject to the terms of the Lease and the

Original Work Letter (but there shall be no fee due to Landlord as a part of the installation or consent to the installation of the washer or dryer). The washer must be placed in a tub with a drain and the dryer must be a condensor clothes dryer such that no heat and no moisture shall be exhausted within the Building, as no exterior ventilation for such dryer is or will be permitted. The amount of water use associated with the washer shall be sub-metered, using a sub-meter to be paid for by Tenant, and Tenant shall pay for any water use by said washer, within the time periods for payment required under the Lease. To the extent that the electrical loads required to properly operate such washer and dryer exceed the Building standard electrical loads, then electrical usage of such shall also be separately metered using a sub-meter paid for by Tenant, with Tenant also paying for any extra electrical u