EX-10.1: CO-INVESTOR JOINDER AGREEMENT

Exhibit 10.1

CO-INVESTOR JOINDER AGREEMENT

          THIS CO-INVESTOR JOINDER AGREEMENT (“Co-Investor Joinder Agreement”), dated as of September 21, 2007, by and among FIRST ALBANY COMPANIES INC., a New York corporation (the “Company”), MATLINPATTERSON FA ACQUISITION LLC, a Delaware limited liability company (the “Investor”), and ROBERT M. TIRSCHWELL (the “Co-Investor”).

RECITALS

     A. The Investor and the Company have entered into an Investment Agreement dated as of May 14, 2007 (the “Investment Agreement”).

     B. Pursuant to the Investment Agreement, the Investor has the right to designate one or more Co-Investors to purchase a portion of the Purchased Shares in the place of the Investor.

     C. The Co-Investor and the Investor have entered into a Co-Investment Agreement dated as of September 21, 2007 pursuant to which the Co-Investor and the Investor have agreed that the Co-Investor will become a “Co-Investor” for the purposes of the Investment Agreement and by notice to the Company of even date therewith, the Investor has designated the Co-Investor as such a “Co-Investor” for such purposes.

     D. The parties are entering into this Co-Investor Joinder Agreement pursuant to Section 2.1(c) of the Investment Agreement.

     NOW THEREFORE, in consideration of the mutual promises and covenants set forth herein, and for such other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereby agree as follows:

     1. Definitions. Capitalized terms used but not defined herein shall have the meanings ascribed to such terms in the Investment Agreement.

     2. Purchase and Sale of Stock. Subject to the terms and conditions hereof, and the closing conditions set forth in the Investment Agreement, at the Closing, the Company shall issue and sell, and the Co-Investor shall purchase, the number of Purchased Shares (the “Co-Investor Shares”) corresponding to an aggregate purchase price of $450,000 (the “Co-Investor Purchase Price”), all on the terms set forth in the Investment Agreement. At the Closing, the Co-Investor shall pay the Company the Co-Investor Purchase Price by instructing the Company to debit the brokerage account maintained by the Co-Investor with the Company in the amount of such Co-Investor Purchase Price.

     3. Joinder. The Co-Investor hereby agrees to become a party to the Investment Agreement as a “Purchaser” thereunder, and agrees to perform, and to be bound by, all the obligations of a Purchaser under the Investment Agreement. The Co-Investor hereby acknowledges that he has received and reviewed a complete copy of the Investment Agreement and the Company’s proxy statement dated August 31, 2007 for its annual meeting to be held on

September 21, 2007. The Co-Investor also agrees to be bound by the Investor Confidentiality Agreement (a copy of which the Co-Investor acknowledges having received and reviewed) as if he were a party thereto.

     4. Representations and Warranties. The Co-Investor hereby represents and warrants to the Company as follows:

     4.1. Capacity.

     The Co-Investor has full capacity to execute deliver this Co-Investor Joinder Agreement and perform his obligations as a Purchaser under the Investment Agreement.

     4.2. Authorization; Execution and Enforceability.

     This Co-Investor Joinder Agreement has been duly executed and delivered by the Co-Investor and constitutes, and by his execution hereof the Investment Agreement constitutes, the legal, valid and binding obligation of the Co-Investor, enforceable against the Co-Investor in accordance with its terms. The Registration Rights Agreement, when executed and delivered by the Co-Investor as contemplated in the Investment Agreement, will have been duly executed and delivered by the Co-Investor and will constitute the legal, valid and binding obligation of the Co-Investor, enforceable against the Co-Investor in accordance with its terms

     4.3. No Conflict; Consents and Approvals.

     (a) Neither the execution, delivery or performance by the Co-Investor of this Agreement, the Registration Rights Agreement or the Co-Investor Joinder Agreement (or the performance by the Co-Investor of the Investment Agreement to which the Co-Investor will become a party pursuant thereto), nor the consummation of any of the Transactions, will result in a breach of, constitute (with or without due notice or lapse of time or both) a default under, result in the acceleration of, create in any party any right to accelerate, terminate, modify or cancel, or require any notice, consent or waiver under, any Contractual Obligation or any Requirement of Law applicable to the Co-Investor or any of his properties or assets, other than a breach, default, acceleration, right, notice, consent or waiver that is not material.

     (b) The Co-Investor is not required to obtain any consent, authorization or approval of, or make any filing or registration with, any Governmental Authority or any self regulatory organization in order for the Co-Investor to execute, deliver and perform the Registration Rights Agreement and this Co-Investor Joinder Agreement (and to perform the Investment Agreement to which the Co-Investor will become a party pursuant hereto), or to consummate the Transactions.

     (c) No material Contractual Consents are required to be obtained under any Contractual Obligation applicable to the Co-Investor in connection with the execution, delivery or performance by the Co-Investor of the Registration Rights Agreement or this Co-Investor Joinder Agreement (or the performance by the Co-Investor of the Investment Agreement to which the Co-Investor will become a party pursuant hereto) or the consummation of any of the Transactions.

     4.4. Purchase Entirely for Own Account.

          The Co-Investor Shares to be acquired by the Co-Investor hereunder will be acquired for the Co-Investor’s own account, not as nominee or agent, and not with a view to the resale or distribution of any part thereof in violation of the Securities Act, and the Co-Investor has no present intention of selling, granting any participation in, or otherwise distributing the same in violation of the Securities Act. The Co-Investor does not have any agreement or understanding, whether or not legally binding, direct or indirect, with any other Person to sell or otherwise distribute the Co-Investor Shares.

     4.5. Investment Experience.

          The Co-Investor acknowledges that he can bear the economic risk and complete loss of its investment in the Co-Investor Shares and has such knowledge and experience in financial or business matters that he is capable of evaluating the merits and risks of the investment contemplated hereby. The Co-Investor understands that the purchase of the Co-Investor Shares involves substantial risk.

     4.6. Disclosure of