FIRST MODIFICATION TO NOTE AND STOCK PLEDGE AGREEMENT

Exhibit 10.13

FIRST MODIFICATION TO NOTE AND STOCK PLEDGE AGREEMENT

Loan #4027203-101

This First Note Modification Agreement (hereinafter “Agreement”) is made and entered into this 20th day of JULY 2007, by and between SECURITY BANK CORPORATION, (hereinafter “Borrower”) and THE BANKERS BANK, a Georgia banking corporation (hereinafter “Lender”).

WITNESSETH:

WHEREAS, Borrower did execute and deliver to the Lender a Promissory Note (hereinafter “Note”), dated JULY 20, 2005 in the original principal amount of SEVENTEEN MILLION DOLLARS AND NO/100 ($17,000,000.00) DOLLARS, with a maturity date of JULY 20, 2007; and

WHEREAS, Borrower and Lender have agreed to modify the original Note and Stock Pledge Agreement by extending the draw period under the note, by extending the maturity date, and by modifying the covenants of the loan agreement;

NOW THEREFORE, in consideration of the foregoing premises and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Borrower and Lender do hereby agree as follows:

NOTE

The Note is hereby modified and amended as follows:

LOAN AND STOCK PLEDGE AGREEMENT

The Loan and Stock Pledge Agreement is hereby modified and amended as follows:

“The Borrower shall not permit its Tangible Capital, not excluding any injection of capital from trust preferred facilities, to be less than $79,000,000,00”:

And replacing it with:

“The Borrower shall not permit its Tangible Capital, not excluding any injection of capital from trust preferred facilities, to be less than $150,000,000.00”;

“The Borrower shall not permit the allowance for loan and lease losses of any of the Bank Subsidiaries to be less than 1.00% of its gross loans for each year-end.”

PROMISSORY NOTE

FOR VALUE RECEIVED , the undersigned, Security Bank Corporation , a Georgia corporation (the “Borrower”), promises to pay to the order of THE BANKERS BANK (the “Lender” and, together with any holder hereof, called the “Holder”), at 2410 Paces Ferry Road, 600 Paces Summit, Atlanta, Georgia 30339-4098 (or at such other place as the Holder may designate in writing to the Borrower), in lawful money of the United States of America, the principal sum of Twenty Two Million AND NO/100 DOLLARS ($22,000,000.00) , or so much thereof as may hereafter be disbursed hereunder, together with interest on so much thereof as is from time to time outstanding and unpaid, from the date of each advance of principal at a rate of interest as hereinafter provided.

This Note is the Note made and given as described in that certain First Modification To Note and Stock Pledge Agreement of even date, between the Borrower and the Lender. Such Loan and Stock Pledge Agreement as modified from time to time is referred to herein as the “Loan Agreement”. In the event of any inconsistency between this Note and the Loan Agreement, this Note shall control. All capitalized terms used herein shall have the meanings ascribed to such terms in the Loan Agreement, except to the extent such capitalized terms are otherwise defined or limited herein.

Subject to the terms and conditions of the Loan Agreement, the Lender will make advances of the principal amount hereunder as requested from time to time by the Borrower. Each such advance will reduce the remaining commitment to lend hereunder and repayments of advances shall permit the Borrower to receive a re-advance of such funds. No advance shall be made after July 20, 2009 .

The Borrower hereby authorizes the Holder to endorse on the Schedule annexed to this Note all advances of funds made to the Borrower and all payments of principal amounts in respect of the Loan, which endorsements shall, in the absence of manifest error, be conclusive as to the outstanding principal amount of the Loan; provided, however, that the failure to make such notation with respect to any Loan or payment shall not limit or otherwise affect the obligations of the Borrower under this Note.

The Borrower promises to pay interest on the unpaid principal amount outstanding hereunder (the “Loan”), at a simple interest rate per annum equal to the Prime Rate Basis. “Prime Rate Basis” shall mean, on any day, a simple interest rate per annum equal to the Prime Rate minus one hundred basis points (1.00%) .

“Prime Rate” shall mean, on any day, the rate of interest published as the “Prime Rate” as of such day appearing in the “Money Rates” section of the Wall Street Journal , Eastern Printed Edition, or any successor to such section. If more than one such rate shall be published, then the Prime Rate shall be the higher or highest of such rates. The

Prime Rate in effect as of the close of business of each day shall be the applicable Prime Rate for the day and each succeeding non-business day in determining the applicable Prime Rate Basis.

Interest shall be calculated on the basis of a 360-day year for the actual number of days elapsed.

Interest under this Note shall be due and payable quarterly in arrears on the first day of each calendar quarter, commencing October 1, 2007, and continuing to be due on the first day of each calendar quarter thereafter until this Note is paid in full. Interest shall also be due and payable when this Note shall become due (whether at maturity, by reason of acceleration or otherwise). After default, interest shall also be due and payable upon demand from time to time by the Holder as provided below.

The principal under this note shall be due and payable at maturity. The entire outstanding balance of the indebtedness evidenced by this Note, together with all accrued and unpaid interest, shall be due and payable on July 20, 2009.

Overdue principal shall bear interest for each day from the date it became so due until paid in full, payable on demand, at a rate per annum (computed on the basis of a 360-day year for the actual number of days elapsed) equal to the Prime Rate Basis plus 3%.

In no event shall the amount of interest due or payable hereunder exceed the maximum rate of interest allowed by applicable law, and in the event any such payment is inadvertently paid by the Borrower or inadvertently received by the Holder, then such excess sum shall be credited as a payment of principal, unless the Borrower shall notify the Holder, in writing, that the Borrower elects to have such excess sum returned to it forthwith. It is the express intent hereof that the Borrower not pay and the Holder not receive, directly or indirectly, in any manner whatsoever, interest in excess of that which may be lawfully paid by the Borrower under applicable law.

All parties now or hereafter liable with respect to this Note, whether the Borrower, any guarantor, endorser, or any other person or entity, hereby waive presentment for payment, demand, notice of non-payment or dishonor, protest and notice of protest, or any other notice of any kind with respect thereto.

Time is of the essence of this Note.

No delay or omission on the part of the Holder in the exercise of any right or remedy hereunder or any Financing Document, or at law or in equity, shall operate as a waiver thereof, and no single or partial exercise by the Holder of any right or remedy hereunder, under the Loan Agreement or any Financing Document, or at law or in equity, shall preclude or estop another or further exercise thereof or the exercise of any other right or remedy.

Should this Note, or any part of the indebtedness evidenced hereby, be collected by law or through an attorney-at-law or under advice therefrom, the Holder shall be entitled to collect reasonable attorneys’ fees and all costs of collection.

This Note is entitled to the benefits of the Loan Agreement, which contains provisions with respect to the acceleration of the maturity of this Note upon the

And replacing it with:

“For any subsidiary Bank, Allowance for Loan and Lease Losses (ALLL) shall be at least 1.00%, measured at fiscal year-end. If GAAP requires that the ALLL be reduced to a level lower than 1.00%, this percentage shall be considered for the covenant measurement.”

The Note, Loan and Stock Pledge Agreement, and other Documents are hereby modified and amended to reflect the availability increase and modification of covenants. All other terms, conditions and warranties contained within the Note, Stock Pledge Agreement, and other Documents executed in connection therewith shall remain in full force and effect in exact accordance with the terms thereof, except where modified, ;

The parties acknowledge and agree that this shall not constitute a novation of the obligations and liabilities of any of the documents executed in connection therewith or a release of any collateral or security therefore or a waiver of any rights or remedies of the Lender thereunder, such rights being specifically reserved by the Lender. Borrower hereby ratifies, confirms and acknowledges each warranty and obligation of the Borrower contained in the Note, Loan and Stock Pledge Agreement, and other Documents, and in consideration of the extension of the draw period by the Lender, Borrower both for himself and his heirs, representatives and assigns, waives any defenses that he may have, whether known or unknown, to the enforcement by the Lender of all obligations of the Borrower contained in all the documents now in force or executed simultaneously herewith.

This Agreement shall be construed, governed by and enforced in accordance with the laws of the State of Georgia.

This Agreement has been made and entered into the day and year first written above.