U.S. and European negotiators agreed Saturday to a 75-day cooling-off period in their increasingly abrasive trade war involving American beef containing growth hormones as they intensified their search for a compromise to resolve the dispute.

U.S. Trade Representative Carla Hills, holding her first discussions as the Bush administration's top trade negotiator, said that substantial progress had been made in the two days of talks with representatives of the 12-nation European Community.The two sides agreed to establish a high-level task force to study the issue over the next 75 days with the goal of coming up with ways to export hormone-free American beef to Europe.

The task force will also consider an American demand that a panel of experts should be established to consider whether growth hormones constitute a health risk.

"We made good progress in working out a procedure with respect to our differences in the hormone area," Hills told reporters. "We have a high-level task force to deal with that issue, to work out the differences if at all possible."

Frans Andriessen, the top trade negotiator for the European Community, said that he was encouraged by the talks with the new administration and predicted "our good will and good spirit" would guide the way to a solution.

Both President Bush and European officials have expressed a desire to defuse the trade dispute, fearing that the battle could aggravate tensions just at a time when the new administration is trying to forge closer ties with its European allies.

The current trade dispute began on Jan. 1 when the Europeans imposed a ban on shipments of U.S. beef because the meat contained growth hormones used to fatten American cattle.

The Reagan administration charged that the European action, which affected about $100 million in annual meat shipments, represented an unfair trade barrier and that there was no scientific evidence that the hormones were a health threat.

In retaliation, the Americans slapped 100 percent tariffs on $100 million worth of European products, ranging from canned tomatoes to fruit wines and instant coffee. Those tariffs are just now showing up in higher prices at U.S. grocery stores.