Me. Rev. Stat. tit. 9-A, § 9-311

A creditor may not, in connection with the extension of credit, interfere with a purchaser's or borrower's free choice of an accounting, tax or attest services provider who is accredited as a certified public accountant, public accountant or enrolled agent, except that the creditor may require the provider chosen by the purchaser or borrower to provide adequate evidence of liability insurance or such other written policy requirements as the creditor may determine necessary to protect its interest.