Robert Maguire III, developer of many of the skyscrapers in downtown Los Angeles, has abandoned his last-ditch effort to buy the company that he founded and has been forced out as chief executive and chairman, according to people familiar with the matter.

The board of Maguire Properties Inc., under pressure from hedge-fund investors, voted Saturday to replace Mr. Maguire as CEO with Nelson Rising, a former Maguire executive who later ran another real-estate company, Catellus Development Corp., people said.

The board also installed director Walter Weisman, who chaired the independent committee that was exploring strategic options, as Maguire's chairman.

Associated Press The 72-story U.S. Bank Tower in Los Angeles, a Maguire trophy.

Mr. Maguire, 73 years old, has been struggling for months to buy at least part of the company himself and as recently as Thursday morning was still talking to his partner, Brookfield Properties Corp., in his latest proposed deal. But he informed those involved that he was dropping his efforts to buy Maguire.

Mr. Maguire continued to negotiate with the board Friday to maintain some face-saving role in running the company, people said. It is not clear whether he was successful in doing this. Mr. Rising couldn't be reached. Mr. Weisman and Mr. Maguire didn't return calls seeking comment.

Mr. Maguire was hampered by the credit crisis and the weakening economy in his efforts to hold on to his company. A number of buyers, including Brookfield, have expressed interest in Maguire's Los Angeles portfolio. But the sluggish office-building market made a sale of the entire company difficult, particularly Maguire's Orange County properties, which lost many tenants involved in the subprime-mortgage industry.

The boardroom coup amounts to a humbling end for Mr. Maguire, a prolific developer who has been buying and building office buildings since 1966.

Like many other large real-estate companies, Maguire Properties attempted to sell itself at the top of the market, when Maguire's stock was trading at $35 to $40 a share. But unlike most others, it couldn't pull off a deal. Maguire shares fell $1.35, or 8.2%, to $15.20 as of 4 p.m. in New York Stock Exchange composite trading Friday.

More recently, after Maguire's stock fell, the company came under siege by hedge funds that purchased a sizable stake in the company and urged the Maguire board to put the company up for sale. Maguire Properties has long underperformed its office peers and is highly leveraged for a public real-estate company. It also has been criticized for spending $2.8 billion to buy a portfolio of 24 office buildings in Los Angeles and Orange County in February 2007 just months after trying to sell itself.

Write to Jennifer S. Forsyth at jennifer.forsyth@wsj.com

Bank of Baroda, UAE Real Estate Firm Sign MoU

Centro’s Structure Fends Off Creditors

Family Feud Upsets Asian Firm