MPG Office Trust Inc. late Thursday said that Chief Executive Nelson C. Rising had resigned in a blow to the office landlord as it attempts to recover from the real estate downturn.

The resignation is effective Monday, said the Los Angeles real estate investment trust. Chairman Paul M. Watson will serve as interim chief executive until a successor is named.

Rising acknowledged in his resignation letter that he and board directors agreed on the need to recapitalize the REIT’s finances as it sells inventory, but differed on how to do it.

“I believe the board of directors and I do not share a common vision for the strategic direction of the company and a capital structure necessary to achieve it,” he wrote.

A person close to the situation said Rising leaves on amicable terms. “Nothing was forced. It was his idea and his initiative,” the source said.

A company spokesperson could not be reached for comment.

The REIT changed its name from Maguire Properties Inc. in May to distance itself from founder Robert F. Maguire III, who continues to be a large shareholder. Rising took over as CEO after Maguire left company more than two years ago following a failed attempt to take it private.

The company got into trouble after purchasing a $3 billion office portfolio at the top of the market in 2007. The value of the portfolio plunged when scores of its Orange County tenants in the subprime lending business closed shop.

MPG last week reported a narrower net loss in the third quarter as it continued to sell off non-core assets, a strategy that Rising had aggressively pursued to lower the REIT’s debt load and refocus on its core downtown properties. The company owns downtown’s tallest building, the U.S. Bank Tower.

Shares earlier closed down 8 cents, or 2.74 percent, to $2.84 on the Nasdaq.