NASD announced Monday that it has agreed to principle terms to sell its interest in the American Stock Exchange to GTCR Golder Rauner LLC, a Chicago-based private equity firm, for approximately US$110 million.

The deal is subject to the completion of definitive sale documents and approvals by the NASD’s Board of Governors, Amex’s Board of Governors, vote of the Amex membership and the Securities and Exchange Commission.

“One of our key goals over the last few years has been to exit NASD’s ownership of exchanges, and to focus our entire organization on NASD’s core mission as a regulator to promote market integrity and protect investors,” said Robert Glauber, chairman and CEO of NASD. “The agreement announced today is an important milestone in a continuing process that we hope will ensure a sound future for the Amex and its constituencies.”

Commenting on the agreement, Salvatore Sodano, Amex chairman and CEO said, “The agreement reached with GTCR should ensure that a strengthened Amex can continue to be a vital participant in our financial markets, with leading franchises in options, exchange-traded funds and equities, while remaining an important employer in New York City.”

NASD intends to use proceeds from the transaction to fulfill all of its obligations to enhance Amex’s infrastructure and operations which it undertook in1998 when the exchange was acquired.