Mayor Marion Barry lashed out yesterday at a congressional attempt to require competitive bidding for all District contracts, saying it would undermine the city's efforts to promote minority business.

"The real reason I think this issue was raised . . . is the fact that we spent over $150 million on minority contracts [last year]," Barry said following a ceremony at the District Building in which the city was cited for its minority contracting program. "Some people don't like that."

Barry said his administration would mount a campaign to turn back the amendment, which was tacked on to a fiscal 1986 District spending bill last week by the House Appropriations Committee.

"In the next few days we are going to educate the Congress as to how competitive we are," he said. "The federal government is no example of good procurement. Look at the Defense Department."

The mayor accepted the U.S. Department of Housing and Urban Development's regional Minority Contractors Utilization award, which singled out the city for its efforts to hire minority companies for a range of contracts in the area of housing and community development.

Antonio Monroig, HUD assistant secretary for fair housing and community development, called the city's performance "exemplary" and cited statistics showing the District had awarded 40 percent of its HUD-funded program contracts to minority-owned companies.

In a day dominated by the theme of economic development, Barry also kicked off the city's national marketing program aimed at attracting companies to the District.

Speaking at a luncheon with Curtis McClinton Jr., deputy mayor for economic development, the mayor unveiled the city's new marketing slogan -- "Washington D.C. Is Business" -- and touted a new brochure detailing the city's assets as "the finest piece of marketing I have seen in a long time."

In discussing the contracting controversy with reporters, Barry said that if the amendment requiring competitive bidding for all contracts were approved by the House, the District's efforts to funnel contracts to minority businesses could be squeezed out.

The District's minority business program sets aside 35 percent of its contracts for goods and services for certified minority-owned businesses.

The author of the amendment, Rep. Ralph Regula (R-Ohio), last week criticized the District's contract with Tri-Continental Industries Inc., a fuel oil supplier, and called for competitive bidding across the board. The District awards some contracts noncompetitively on a "sole-source" basis.

Barry denied published reports that the fuel oil contract was awarded without bids from other companies.

"It was awarded competitively and it was extended," he said. "There's nothing wrong with that."

He also responded to charges that the District would save money if it purchased its fuel oil through a cooperative purchasing program run by the Metropolitan Washington Council of Governments. Barry said COG does not have provisions in its program to benefit the minority community.

A spokesman for COG said that individual members of the purchasing cooperative may specify minority contracting requirements for the fuel they buy.