LONDON: Prime Minister Gordon Brown of Britain and President Nicolas Sarkozy of France will urge banks this week to make “full and immediate disclosure” of write-offs resulting from the global credit crisis, Browns office said Monday.

The two leaders are increasingly concerned that confidence in financial markets is being hit by uncertainty over the scale of bad debts on banks books, which some estimates put as high as $600 billion, Browns office said in a statement.

Sarkozy is to hold talks with Brown on Thursday during a two-day visit to Britain as a guest of Queen Elizabeth II.

The two men will “call for greater transparency in financial markets and, as a first step, full and immediate disclosure of the scale of write-offs by banks,” Browns office said.

The bank crisis, especially the collapse of the Wall Street firm Bear Stearns, has shown “the scale of the problem and the effect on market stability of difficult-to-value assets and of undisclosed losses becoming known in a piecemeal fashion,” it said.

Mortgage-backed securities have plunged in value in a credit squeeze brought by low-quality mortgages in the United States, leading to a vicious circle of forced sales, falling prices and weakening balance sheets for banks.

Banks have written down more than $125 billion in assets since November, hammering their shares.

So far, action by central banks and governments has failed to halt the market turmoil.

Sarkozys visit is seen by the British news media as part of his drive for a close partnership with Brown.

The two leaders will call for more talks with the United States and other countries on “measures to promote financial stability” in forums like the Group of 7 industrialized countries, the International Monetary Fund and World Bank, Browns office said.

Brown, Sarkozy and the leaders of Germany and Italy met in London in January to discuss the financial crisis.

The highest profile victim of the crisis in Britain has been Northern Rock, a mortgage lender that Browns government ended up nationalizing.

The financial turmoil has damaged Browns reputation for economic competence and helped the Conservatives extend their lead in the opinion polls over Browns Labour Party.

Sarkozy and Brown will repeat calls for credit rating agencies to be more transparent and for international financial institutions to provide early warning of financial risks to the global economy.

The two men will call for changing the United Nations Security Council to make it more representative, including permanent representation for Africa, Browns office said. Britain and France are among the five permanent members of the council.

Brown will talk to Sarkozy about a possible French contribution to a civilian force consisting of police officers, judges and administrators that Britain plans to set up to help countries get back on their feet after conflicts, Browns office said.

Stock markets soared Monday on Wall Street after a higher offer seemed to salvage a bailout of the investment bank Bear Stearns and investors received a lift from an unlikely source: the housing market, which snapped a six-month streak of declining sales.

The Dow Jones industrials gained more than 240 points Д its second consecutive triple-digit advance Д as investors cheered both developments, which offered band-aids to two of the economys most beaten-up sectors.

Shares of big builders like Lennar and D.H. Horton rose and financial services firms gained, sending the broad Standard Poors 500-stock index up more than 2 percent. The tech-heavy Nasdaq composite index rose 3.3 percent.

Treasury yields rose as investors moved out of ultra-safe government bonds, a sign that some confidence may have re-entered the financial markets. Agricultural commodities surged, with wheat gaining more than 4 percent, after falling last week. The price of crude oil dipped slightly to $101.60, and the dollar gained against the euro.

But the resurgence may be short-lived: the Dow has swung more than 2 percent for four consecutive trading sessions, an enormous amount of volatility.

Indeed, each of the days developments came with a caveat. The $10-a-share deal for Bear Stearns, which has the support of the Federal Reserve, will allow JPMorgan Chase to take over the beleaguered investment bank despite a shareholder revolt that threatened to run the deal off the rails. Bear Stearns stock skyrocketed to $12.44 a share, and JPMorgan shares rose 3 percent.

The deal was received last week as a sign the Fed was finally finding a way to restore confidence in the credit markets. But the fact that a major investment bank effectively failed underscored anxieties on Wall Street that the current financial crisis may be one of the worst in decades.

On the housing front, sales of previously owned homes unexpectedly rose in February, ending a six-month losing streak and offering some relief to owners who had watched sales fall to record lows in recent months.

But home prices continued to plunge Д in February, they had their worst year-over-year drop since records began Д and economists warned that the 2.9 percent sales increase may not signal an end to the housing slump.

Existing-home sales, which make up most of the American housing market, advanced to a seasonally adjusted 5.03 million annual rate, up from 4.89 million in January, according to the National Association of Realtors, a trade group.

But the median price of a previously owned home declined in February to $195,900, an 8.2 percent drop from the period a year earlier.

Inventories, which ballooned in the last year, fell back slightly in February, with the backlog of unsold homes declining 3 percent to 4.03 million units, a 9.6-month supply at the current sales rate. The supply of single-family homes fell but the backlog of condominiums and co-op apartments rose.

“Inventories are very high relative to sales rates, and would probably be even more so if all those wishing to sell their home actually had the house on the market,” wrote Joshua Shapiro, chief United States economist at MFR, a New York research firm. “While price declines seen so far represent a reasonable start, we still have a long way to go.”

In another positive development for the housing industry, a major government-backed mortgage lender received permission to purchase $150 billion in mortgage-backed bonds guaranteed by Fannie Mae and Freddie Mac, a move that may make it easier for Americans to take out home loans.

The decision came a week after Fannie and Freddie announced that their own regulator had freed up an additional $200 billion for the same purpose.

NEW YORK: Carl Icahn, the billionaire investor with a history of initiating hostile actions against companies, said Monday that he was suing Motorola to force it to hand over documents related to its money-losing mobile devices unit and determine if the board of the company had failed in its duties.

Icahn, the second-biggest shareholder in Motorola, is engaged in a proxy battle with the company and has proposed a slate of four directors to the board of the company, whose market share lags behind those of Nokia and Samsung Electronics.

Motorola had previously announced that it was looking at options including a separation of its mobile devices business, following pressure from Icahn.

The Icahn Group on Monday said it had filed a lawsuit in a Delaware court seeking documents related to Motorolas mobile devices business, including board discussions about a potential spinoff and the units performance.

“We demanded these materials for the purposes of enabling us to investigate whether and to what extent the board of directors of Motorola failed in their duties as directors,” Icahn said in a letter to Motorola shareholders.

Icahn also asked for documents, if there are any, showing use of Motorolas aircraft and property by senior management, the board of directors and their families. The investor also questioned whether Greg Brown, recently appointed as chief executive, was qualified for the job.

Icahn holds about 6.3 percent of Motorola.

Icahn promised to share the released information with Motorola stockholders, but added that Motorola had said it would not comply.

A Motorola spokeswoman, Jennifer Erickson, said the company had not yet received a copy of the lawsuit but would review it in due course.

Motorola, which has said it faces a challenging 2008, has been losing to rivals such as Nokia and Samsung in the last year amid criticism of its cell phone line-up and failure to produce a strong successor to the once-lauded Razr phone.

Charter Equity Research analyst Ed Snyder said that Icahn, who failed to win a Motorola board seat last year, was likely looking for information that would help him win shareholder support ahead of the annual meeting, set for May 5.

“Hes trying to wrest control of the company because he thinks his slate can do a better job than the current board, which is not a high bar,” said Snyder who expects shareholders to be more open to Icahn at this years director election.