Santa Ana-based Grubb & Ellis Co. has rejected former chairman Tony Thompson's request for a board seat on the slumping real estate company.

The company "has considered your request and after careful consideration has determined that it would not be in the best interests of the company's stockholders for you to rejoin the board," Glenn Carpenter, Grubb & Ellis' current chairman, said in a letter to Thompson.

The letter was filed with the Securities and Exchange Commission earlier this week.

Thompson, Grubb & Ellis's second-largest shareholder, said in late June he was unhappy with the real estate investor and brokerage's stock performance, and sought re-appointment to the company's board.

It's unclear what his next move will be.

Thompson stepped down from the board and his chairman seat early this year, after his former company, NNN Realty Advisors, acquired Grubb & Ellis in a reverse merger.

Grubb & Ellis' stock has slumped since the acquisition, due in large part to troubles in the commercial real estate market.

The company now counts a market value of about $240 million, well below the $750 million value given to the combined company at the time the acquisition was announced in 2007.

Grubb & Ellis' chief executive, Scott Peters, stepped down earlier this month and was replaced on an interim basis by Gary Hunt, a director for the company.

Thompson started up a new real estate investment firm, Irvine-based Thompson National Properties LLC, a few months ago.