A coalition of black business and political groups has extracted a commitment from a key Washington Suburban Sanitary Commission official to initiate new policies that could increase the number of contracts that go to minority firms and increase the number of black administrators at the agency.

After two weeks of debate and allegations that the WSSC has failed to give minority-owned businesses a fair share of construction and procurement contracts, the Prince George's County Council yesterday confirmed the reappointment of commissioner Robert M. Potter to the utility authority. Potter's reappointment was postponed after black elected officials and business and civic leaders said that while he was chairman he did little to direct more contracts to minority businesses, an allegation he has denied.

Opposition to Potter faded after a meeting Monday, at which he agreed to help develop an affirmative action plan to raise the number of blacks in top management at the WSSC to a minimum of 30 percent; develop a program to award at least 30 percent of all WSSC procurement, construction and professional services contracts to minorities, and support state legislation that would create a sheltered market for minority companies for WSSC construction contracts. He also agreed to support expansion of the agency's Minority Business Enterprise staff to four persons.

Any changes in the minority business program or hiring practices still must be approved by the six-member commission. The black leaders said they are lobbying the other commission members to approve these goals, and that it was important to get Potter on board.

The sheltered market program, which reserves certain contracts for minority-owned companies, requires General Assembly approval.

"The agreement we have reached is another step in improving WSSC," said John Spearmon, chairman of of the Coalition of Black Economic Development. "This is only a beginning as far as the black community is concerned. No longer can legitimate concerns and issues be ignored."

However, some political observers said that the WSSC already has exceeded some of its minority contracting goals. The WSSC has an affirmative action plan and supports proposed legislation to create sheltered markets.

For the fiscal year ending June 30, the WSSC has awarded 25.9 percent of $64 million in procurement contracts to companies owned by blacks, women, Hispanics and Asians. The agency awarded 11.5 percent of $58 million in pipelaying construction contracts to minority companies, exceeding its goal of 10 percent. No figures were available for minority participation in other contracts.