Representatives of the District's sidewalk vendors agreed yesterday to accept Mayor Marion Barry's proposal for easing some of the city's new regulations for sidewalk merchants and are considering dropping legal action against the city in exchange.

"There was a trade-off," said Kwasi Abdul Jalil, a vendor leader who characterized Barry's decision as a major concession. "The bottom line was that we would cut out our legal madness and they city officials would cave in on some of the issues."

Business representatives, who have long opposed sidewalk vending, yesterday wrote the mayor protesting the changes.

The new vending regulations went into effect on May 15, but the city had agreed not to begin enforcement until today. Barry's agreement with the vendors delays the enforcement for 16 more days until June 30.

Last month, the vendors lost a suit filed in U.S. District Court to have the rules declared unconstitutional on grounds that they unfairly benefited store merchants while restricting sidewalk salesmen from doing business.

The vendors have sought reconsideration of the court decision.

Yesterday, Jalil and Melvin Marshall, a lawyer representing the vendors, said that Barry had requested that the vendors take no further legal action.

Marshall said the vendors would agree to that condition if the mayor was prevented from altering his decision to modify the regulations.

Jalil said that according to city officials, the modifications included lifting the ban on selling manufactured merchandise, such as clothing, and dropping the requirement that vendors of nonfood items use wooden carts.

Last year, the District had more than 5,200 licensed vendors and new rules, even modified, would reduce that number to 2,900 in the downtown area and 1,310 in residential neighborhoods.

Barry's decision to change the regulations has angered some members of the business community who have charged that vendors do not pay their share of city taxes, giving them an unfair advantage over store merchants, and creating safety problems along sidewalks.

Donald Slatton, executive vice president of the Apartment and Office Building Association, said representatives from local businesses will meet Monday to discuss what legal and political actions they can take in response to Barry's actions.

Slatton, in a letter hand-delivered to the mayor yesterday, reminded Barry that the regulations had been developed over a two-year period and represented a compromise.

"On behalf of our members, and our thousands of retail merchant tenants, we strongly protest your action," wrote Slatton. "We urge you to allow the compromise regulations to go into effect. To do otherwise is to make a statement to the office building industry that participating in the governmental process will not work and that your administration is not interested in our doing so."

Vendors had viewed the new rules as an attempt by store merchants to stifle low-cost competition.

Vendors had printed 1,500 posters depicting Barry as a puppet controlled by the Greater Washington Board of Trade and pointing a shotgun at a vendor.

Only a few of the posters had been displayed in public. Yesterday, some vendors said Barry has demonstrated that he is sensitive to them.

"A lot of vendors are not professional business people but are scuffling to make an honest living," said Sam Nelson, who has been a vendor here for 15 years. "Some people would have had to go on welfare to survive. I think that is why the mayor made some of the concessions he did."