U.S. banks agreed yesterday to extend for the rest of this year a freeze on repayment of loans Poland owes to U.S. private financial institutions but dug in their heels on longer-term rescheduling as favored by European banks and governments.

Banking sources familiar with the talks in New York yesterday said that the American banks are reluctant to agree to conditions that would put the Polish loans on terms they would consider unsound, even though it is generally recognized that Warsaw desperately needs cash to pay interest on its huge international debt and to finance sorely needed imports.

The U.S. banks announced they would recommend a six-month freeze on repayment of principal on the debts while studies of the Polish economy are undertaken, and actions by the Warsaw government to put its economy in order are closely monitored. The U.S. banks would require regular repayment of interest on the loans during the freeze.

West European and Japanese banks, which hold the bulk of Poland's $15 billion private foreign debt, have been pressing for an immediate long-term rescheduling to east Poland's cash crisis. Poland's total foreign debt, including government loans, is in excess of $20 billion, and Warsaw has asked Western banks and governments for an $11 billion rescue package to get through the current economic squeeze. The U.S. private banks' share of the private loans to Poland is $1.4 billion.

Poland's economic situation was tenuous before the outbreak of economic and political unrest almost a year ago and has gone rapidly downhill as the country has grappled with its political and social future.

A State Department official said yesterday that while the Reagan administration "would prefer to see a settlement" immediately, he was "not excessively worried so long as the banks continue to work on making progress." He added that the extension of the freeze was "not apparently less favorable for the Poles in practical terms."

Banking sources said the action of the U.S. banks has "tremendous symbolic importance," clearly reflecting concern about the immediate political future of Poland, and the possible effects this could have on an already battered economy.

The recommendation for an extension of the freeze will go to a 12-nation task force of 19 banks that is meeting on June 24 to decide what to do about Poland's virtual bankruptcy. Other members of the task force are expected to rpess for immediate restructuring of the debt, and could decide to go ahead with this, leaving the U.S. banks alone, sources said yesterday.

The decision to oppose an immediate rescheduling was announced by Bankers Trust yesterday on behalf of 63 U.S. banks with outstanding loans to Poland. The National Coordinating Committee of the U.S. banks actually made the decision a week earlier, sources said.

The U.S. bankers said they are willing to continue "to provide as much trade financing" as possible during the six month freeze, a spokesman for Bankers Trust said yesterday. The freeze also means that no default would be declared, even though Poland is unable to keep up with repayments of principal.

West German banks, which are most heavily involved, wanted U.S. banks to take the lead in negotiating a rescheduling of its Western debt, a New York source said. However, the U.S. banks have consistently opposed any restructuring other than on strictly commercial terms, reportedly arguing that an immediate rescheduling could amount to throwing good money after bad.

The other banks, particularly those in Western Europe, have more at stake financially and politically, sources said, and are more influenced by their governments and central banks who want an immediate settlement to ease political tensions.

They found the U.S. action "extremely distressing," banking sources said yesterday. It is possible that they will decide to go ahead with a renegotiation while the U.S. banks alone extend the freeze.

The 12-nation group in the task force includes banks from West Germany, Austria, Britain, France and Japan. It had set a deadline of June 30 for agreement on a debt restructure, after Poland declared that it could not keep up its payments in the second quarter of this year. Repayments of principal have been unofficially frozen since the end of March. r

Western governments have already agreed to reschedule the $12 billion to $15 billion of government backed debt outstanding to Poland. Although this was originally conditional on the commercial banks reaching a similar agreement, sources yesterday said that the U.S. decision was not expected to hold up the office restructuring.

Poland will need about $12.5 billion cash this year, a banker said yesterday. Of this it has $5.1 billion from a combination of new credits and the government rescheduling, and will get more if the non-U.S. banks go ahead with a restructuring. But it will still fall several billion dollars short of needs, a source said, and "it is an open-ended question" where it will get the money. The Soviet Union has told Poland that it will not give any more cash until at least the last quarter of this year.