Exhibit 5.1


                    SCHELL BRAY AYCOCK ABEL & LIVINGSTON PLLC
                          SUITE 1500 RENAISSANCE PLAZA
                              230 NORTH ELM STREET
                        GREENSBORO, NORTH CAROLINA 27401




                                                    June 13, 2007




         FNB United Corp.
         150 South Fayetteville Street
         Asheboro, North Carolina 27203

          Re:  725,000 shares of Common Stock, par value $2.50 per share, of FNB
               United Corp. offered in connection with the FNB United Corp. 2003
               Stock Incentive Plan Ladies and Gentlemen:

                  We have acted as counsel for FNB United Corp., a North
         Carolina corporation (the "Corporation"), in connection with the filing
         of a registration statement on Form S-8 (the "Registration Statement")
         under the Securities Act of 1933, as amended, with respect to 725,000
         additional shares of the Corporation's common stock, par value $2.50
         per share (the "Shares"), to be issued to participants in the
         Corporation's 2003 Stock Incentive Plan (the "Plan").

                  We have examined such documents, records and matters of law as
         we have deemed necessary for purposes of rendering this opinion. For
         purposes of this opinion, we have assumed the genuineness of all
         signatures, the authenticity of all documents submitted to us as
         originals, the conformity to originals of all documents submitted to us
         as certified, photostatic or conformed copies, and the authenticity of
         the originals of such documents.

                  We are qualified to practice law in the State of North
         Carolina. We do not purport to express any opinion herein concerning
         any law other than the laws of the State of North Carolina and the
         federal securities laws of the United States.

                  Based upon the foregoing, we are of the opinion that the
         Shares that may be issued and sold by the Corporation pursuant to the
         Plan are duly authorized and will be, when issued and sold in
         accordance with such Plan, validly issued, fully paid and
         nonassessable.

                  We hereby consent to the filing of this opinion as Exhibit 5.1
         to the Registration Statement.

                                     Very truly yours,

                                /s/  Schell Bray Aycock Abel & Livingston PLLC