Washington - The United States on Friday unveiled part of a massive, comprehensive plan to help resolve the ongoing US financial crisis and prevent a rush of new bank failures in the coming weeks.

The US Treasury announced a 50-billion-dollar guarantee programme for the money-market mutual fund industry, the first in a series of moves that could come Friday after overnight talks with congressional leaders. US media reported the entire rescue package could cost as much as 500 billion dollars.

The element unveiled Friday morning aims to ease concerns of investors who had been pulling out of money markets mutual funds in response to the financial turmoil of this week. US stocks have been extremely volatile and banks have begun hoarding cash in response to a shortage of capital in firms that were dealing in mortgage-related assets.

"Money market funds play an important role as a savings and investment vehicle for many Americans; they are also a fundamental source of financing for our capital markets and financial institutions," the Treasury said in a statement.

"Maintaining confidence in the money market fund industry is critical to protecting the integrity and stability of the global financial system," the statement said.

Treasury Secretary Henry Paulson and Federal Reserve Chairman Ben Bernanke briefed congressional leaders on comprehensive measures late Thursday over what could become the largest-ever intervention in US financial markets.

The new moves represent a broader approach to dealing with the crisis, as opposed to the ad hoc government bailouts and stop-gap measures taken since the beginning of this year.

The bulk of the plan could involve creating a new government agency that would absorb billions of dollars in bad loans of banking firms that have been decimated by the plunging value of mortgage-related assets.

The two-part plan to buy both private and government-guaranteed mortgage-backed securities could cost as much as half a trillion dollars, CNBC reported. The larger part of the proposal, which would need to be approved by Congress, would involve buying mortgages underwritten by Wall Street.

The second part would involve buying government-backed mortgages. This would come under a plan the government announced less than two weeks ago, when it took control of government-chartered mortgage giants Fannie Mae and Freddie Mac and pledged 200 billion dollars to keep them afloat.

Also part of the comprehensive plan was for the Securities and Exchange Commission to propose a temporary ban on short-selling, a stock trading technique that critics argue has helped fuel a furious sell-off of financial stocks on Wall Street this week.

The commission on Wednesday banned the most extreme practices related to short-selling. Short-selling itself is legal, but not if linked with spreading rumours that can help an investor's cause.

Paulson was to hold a press conference Friday morning. After briefing congressional leaders late Thursday, Paulson told reporters they were planning "a comprehensive approach that will require legislation to deal with illiquid assets on financial institutions' balance sheets."

"This country is able to come together and do things quickly when it needs to be done for the good of the American people," he said.

Bernanke described the meeting as "very, very positive" and said: "We look forward to working closely with Congress to resolve this financial crisis and get our economy moving again."

While no formal plan or timeframe was announced after the meeting, House of Representatives Speaker Nancy Pelosi said "time is of the essence."

Senate Majority Leader Harry Reid said he expected to see a proposal "in a matter of hours, not days." (dpa)