WASHINGTON—The Federal Reserve said today it is extending its emergency borrowing program to Wall Street firms and is taking other steps to ease a severe credit crunch that has hobbled the national economy.

The Fed said the program, where investment houses can tap the central bank for a quick source of cash, will now be available through Jan 30. Originally the program, started March 17, was supposed to last until mid-September.

Another program, where investment firms can temporarily swap more risky investments for super-safe Treasury securities also will continue through Jan. 30, the Fed said. It also will let commercial banks, in a separate program, bid on cash loans that last longer — for 84 days, besides the 28-day loans now available.

The Fed said it was taking these steps “in light of continued fragile circumstances in financial markets.” The Fed said that the emergency borrowing program for investment houses and the program that lets investment firms temporarily borrow Treasury securities would be withdrawn should the Fed determine that conditions in financial markets are “no longer unusual and exigent.”

The smooth flow of credit is the economy’s oxygen. It permits people to finance big-ticket purchases, such as homes and cars, and help businesses expand operations and hire workers.

 Fallout from a trio of crises — housing, credit and financial — have badly bruised the economy. Growth has slowed and companies have cut hundreds of thousands of jobs.

Investment houses were given similar, emergency loan privileges as commercial banks after a run on Bear Stearns pushed the nation’s fifth-largest investment bank to the brink of bankruptcy. The situation raised fears that other Wall Street firms might be in jeopardy.

In the swap program, which began on March 27, investment firms bidding on the Treasury securities can put up as collateral more risky investments.

These include certain mortgage-backed securities and bonds secured by federally guaranteed student loans.

The program is intended to make investment companies more inclined to lend to each other. A second goal is providing relief to the distressed market for mortgage-linked securities and for student loans.

The Fed also said it will let Wall Street firms place bids on an option to borrow the Treasury securities. Up to $50 billion would be made available for this. The Fed didn’t say when the first auction of this type would be conducted. The notion here is to give firms — unsure whether they might need the Treasury securities — an insurance policy of sorts.

Starting on Aug. 11, the Fed will give banks the option of bidding on 84-day cash loans from the Fed, besides the 28-day loans now available. Specifically, the Fed will conduct biweekly auctions. They will alternate between making available $75 billion in 28-day loans and $25 billion in 84-day loans. The steps expand a program started in December aimed at helping banks overcome their credit problems so that they can keep lending to customers.

The European Central Bank and the Swiss National Bank have informed the Fed that they also will make available to their banks similar 84-day cash loans. To help on this front, the Fed also boosted its credit line with the ECB to $55 billion from $50 billion.

On the other side of the Atlantic, the ECB and the Swiss National Bank announced Wednesday they will make billions of U.S. dollars available to banks still starving for the currency.

The ECB — the central bank for the 15 countries that use the euro — said it will increase the amount of dollars offered to $50 billion in the latest series of operations. The bank will make 84-day loans available starting on Aug. 8 and said operations will continue as long as “needed in view of the prevailing market conditions.” Similarly, the Swiss National Bank said it would start making 84-day loans available on Aug. 12.

————

AP Business Writer Matt Moore contributed to this report from Frankfurt.