The Federal Home Loan Bank Board moved yesterday to ease the financial squeeze on the nation's savings and loan industry while at the same time pumping more money into the ailing mortgage markets.

The board's actions appeared to contradict the new tight money policies set down by the Federal Reserve Board earlier this month in an effort to curb the nation's rising inflation rate.

The bank board voted to reduce the liquidity requirements for savings and loan associations. The move was designed to help the S&Ls cover mounting withdrawals and existing mortgage commitments. The action could result in an additional $1 billion in short-term mortgage money.

At the same time the board proposed allowing thrift institutions to raise their outside borrowing capacity to 20 percent of assets through the sale of revenue bonds, commercial paper and other financial instruments. this could result in almost doubling the current $13 billion borrowing level over the long term.

In a related action, the Department of Housing and Urban Development and the Veterans Administration yesterday raised the interest rate ceiling on FHA-VA mortgages from 10 to 10 1/2 percent to 11 1/2 percent. The higher interest will cost the purchaser of a $60,000 mortgage and additional $45.60 a month.

Jay Janis, chairman of the Home Loan Bank Board, denied that his agency's actions contradicted the new Fed policy.

Janis said in an interview that reduction of liquidity requirements from 6 to 5.5 percent is not inconsistent with the Fed's policy because it decreases the need for savings and loans to borrow in the marketplace at high rates by allowing them to use more funds already in their system. Janis cited President Carter's wish that tightening of credit should not fall disproportionately on housing.

Two days ago Fed Chairman Paul Volcker appealed to bankers to assure adequate funds to homeowners as well as other important sectors of the economy.

Janis added that reductions in liquidity requirements were a routine thing, the last having taken place last January. If the maximum amount of funds were freed up, it would amount to $2.4 billion. He estimated that about half this amount could show up in the mortgage market in the next several weeks. However, this would not affect interest rates which have now reached 14 percent in some parts of the country.

The Fed had no comment on the FHLBB's action. Economist Michael Evans, however, didn't see the action as routine. "It's possible this is a carefully orchestrated move on the part of the administration to cushion the housing industry from monetary blows," he said.

Kenneth Thygerson, chief economist of the U.S. League of Savings Associations, said the amount of new money available after offsetting withdrawals and meeting mortgage commitments would be "minimal." The league announced last week that its 4,468 members had experienced an $800 million outflow last month. Government figures for all S&Ls show a$200 million outflow.

In another development, it was revealed yesterday that the Federal Deposit Insurance Corp. is working on contingency plans to rescue any savings banks in financial trouble. A spokesman said the planning began several months ago as the agency recognized that some savings banks, particularly, in New York, were having problems. The plans involve mergers with sound commercial banks or savings and loan associations. He stressed that the FDIC has no particular banks in mind.

Saul B. Klaman, president of the National Association of Mutual Savings Banks, yesterday called the leaking of the plans to the press "scare tactics." He said savings banks would be forced to reduce mortgage committments, but otherwise their financial situation is better than it was in 1974. Last month its 462 members had a net deposit outflow of $1 billion, a near record.