WASHINGTON (AP) – Treasury Secretary Timothy Geithner and other top officials are putting the finishing touches on a plan to overhaul the government’s $700 billion financial rescue program.

A Treasury official said Geithner will deliver a speech on Monday outlining the new plan.

But Treasury officials would not comment on a report Thursday that the administration is considering changes to the current accounting standard that requires banks to carry assets such as mortgage-backed securities on their books at fair value, a process known as “mark to market.”

Critics of this process contend that it has made the current financial crisis worse by forcing banks to slash the value of assets that are currently depressed because of market conditions. Treasury officials said the administration’s plan was not yet complete and would be revealed in Geithner’s speech in Washington next week.

The idea of modifying the current rules on marking down bank assets is being considered by some key lawmakers as a possible way to address the banking crisis.

House Financial Services Committee Chairman Barney Frank said he was in favor of exploring a modification to the mark-to-market requirements that would give banking regulators more discretion so banks would not face the need to cut lending as a consequence of following those standards.

Senate Banking Committee Chairman Christopher Dodd, D-Conn., said Thursday in an interview that he wanted to consider the possibility of modifying the mark-to-market requirements during times when “you get into a pro-cyclical environment and things are spiraling down. That’s what we are talking about.”

Meanwhile, real estate lobbyists were pressing the government to spend billions to temporarily subsidize lower mortgage rates. They were looking to Geithner’s announcement Monday in hopes that some of the financial rescue money would be used to reduce mortgage rates and prevent foreclosures.

The Federal Reserve has been buying up mortgage-backed securities guaranteed by Fannie Mae, Freddie Mac and Ginnie Mae for a month. Before rising a bit in recent weeks, mortgage rates had plunged since the Fed announced the creation of the $500 billion program late last year.

“They can certainly expand on it to bring the rates down further,” said Lawrence Yun, chief economist with the National Association of Realtors.

Geithner met Thursday with Federal Reserve Chairman Ben Bernanke and other officials who serve on the President’s Working Group on Financial Markets. The group was formed in the wake of the 1987 stock market crash with the goal of better coordinating the government’s response to market crises.

The administration’s overhaul of the controversial $700 billion bailout plan is expected to provide support to banks to deal with some of the toxic assets that are now weighing down their balance sheets and keeping them from resuming more normal lending.

Geithner said the overhaul of the rescue program was aimed at improving the effort to get credit flowing again and to support the Obama stimulus plan being debated in Congress.

The working group also will devote time to discussing the reforms needed to ensure that the current financial crisis, the worst to hit the country in seven decades, is not repeated, he said.

“We also want to use this opportunity to begin the process of shaping a consensus reform of our financial system so that neither the U.S. economy or the global financial system ever … again faces a crisis of this magnitude,” Geithner said.

Besides Geithner and Bernanke, the working group includes Mary Schapiro, the new head of the Securities and Exchange Commission, and Michael Dunn, the acting chairman of the Commodity Futures Trading Commission.

Also meeting with the group were Lawrence Summers, who heads President Barack Obama’s National Economic Council, and Christina Romer, the head of the president’s Council of Economic Advisers.

The discussions also included top banking regulators Sheila Bair, head of the Federal Deposit Insurance Corp., Comptroller of the Currency John Dugan, and James B. Lockhart, director of the Federal Housing Finance Agency, which oversees mortgage giants Fannie Mae and Freddie Mac.