LOS ANGELES-Nelson Rising, the executive that the board of MPG Office Trust brought on to steer a new course for the company when it ousted founder Rob Maguire, has resigned as president and CEO in what Rising calls a disagreement with the board over strategy for the office REIT. “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,” Rising said in a statement issued by MPG. The statement did not list specifics of the disagreement.

Rising, whose resignation is effective Monday, will be succeeded by MPG board chairman Paul M. Watson, who will serve as interim CEO until a new CEO is named. Watson is the retired vice chairman of Wells Fargo Bank.

Rising became CEO of MPG in 2008, when the REIT was still known as Maguire Properties. Rising, a former business partner of Rob Maguire and a former 11-year executive with Catellus Development, since then has led an effort to reduce debt, shed assets that were dragging down earnings and the balance sheet and extend debt maturities.

Analysts trace MPG’s troubles to the debt that Maguire took on to acquire a portfolio of former Equity Office Properties office buildings in Los Angeles and Orange counties from the Blackstone Group for nearly $3 billion in 2007. The bulk of those properties were in Orange County, which has been one of the hardest-hit office markets in the US. After Rising took over, MPG embarked on a plan to reduce debt that included selling some assets and allowing others to go into default, receivership or REO.

In its statement regarding Rising’s resignation, MPG noted that as the first part of its plan to reduce debt, which it launched in August 2009, it ceased making debt service payments on seven properties, primarily located in Orange County, and disposed of or entered into other arrangements for an additional nine properties. That phase is completed and has relieved MPG of approximately $2 billion of debt, along with potential guaranties of approximately $150 million.

The next phase of the REIT’s strategic plan focuses on the company’s core Downtown Los Angeles properties and “involves proactively working with lenders and special servicers in an effort to reduce the company’s leverage, extend debt maturities, maintain appropriate funds for value-creating leasing and capital expenditures and ensure adequate cash flow with respect to these properties,” according to the statement.

Part of the latest phase involves asset dispositions, and MPG has retained Eastdil Secured to start marketing the REIT’s Westin Pasadena in Pasadena as part of that plan. Watson said that MPG is working on “optimizing value and proactively solving future risks at our trophy assets” as part of the plan.