Bank of China, Standard Chartered and Bank of Nova Scotia are among the organizations that have been approached, reports Bloomberg.
The move is understood to be part of an attempt by Thailand to encourage foreign investment in the country's financial sector after it recently relaxed rules regarding overseas ownership.
Under the terms of the deal, the investor would receive the central bank's 47.6 per cent holding in Siam City Bank, which it has valued at $0.99 (33 baht) a share.
At the end of September, the bank possessed total assets of $12.28 million, with liabilities of $10.96 million.
Thailand's central bank plans to start accepting bids for its holding from mid-December and hopes to complete a deal by the end of March next year.
By Claire Archer