Representatives of major U.S. banks met here all day, but were unable to reach a final decision on whether to approve a unified Western position on restructuring Poland's $15 billion debt to U.S., European and Japanese banks.

But a source close to the meeting, held at the Midtown Manhattan headquarters of Bankers Trust Co., said that the 11 banks "look like they're moving toward combining with the European and Japanese position." The U.S. banks, which represent 63 U.S. banks with $1.4 billion in loans to Poland, are expected to meet again next week.

"There's a lot of technical details to be gone over," said a banking source. "But there's no obstructist tone."

Two weeks ago, the U.S. banks balked at the position of most European and Japanese bankers, who wanted to restructure Poland's debt immediately. The U.S. banks said they wanted to put a six-month freeze on the debts and get more economic and financial information from Polish authorities before deciding how to adjust the loans to the strife-torn country.

At a special meeting in Paris last week, a 19-bank task force representing the 460 banks from 12 countries that have lent a total of $15 billion to the Polish regime, agreed to most of the major demands made by U.S. banks. There had been fear that Western banks would not be able to present a unified position to Poland, with the U.S. banks negotiating separately.

Several months ago Poland announced that it no longer could pay on its loans to the West because labor and political unrest had so damaged the country economically. Even before last year's labor uprising. Poland's economic difficulties worried Western bankers.

European and Japanese banks have much more at stake in Poland than do U.S. banks and want not only to restructure the existing debts but also seem willing to lend Poland some more money. The U.ys. banks, while also willing to restructure the current debts into a repayment schedule that Poland can cope with, are being more hard-nosed.

Two weeks ago the U.S. banks said they not only wanted more economic statistics about Poland but also wanted to know its debts to Eastern European countries, including the Soviet Union.

The U.S. banks also want an economic plan from Poland and a series of interim benchmarks against which Poland's econimic and financial progress can be measured. Such benchmarks are used by the International Monetary Fund, of which Poland is not a member, when the agency takes steps to bail out a member country in economic difficulty.

The 19-bank international task force is scheduled to meet on July 24 in Zurich. By then the banking groups in each of the 12 nations, similar to the group that met here today, are supposed to review last week's Paris accord. All 19 banks in Paris approved the agreement.