Prince George's County officials, under pressure from the black community to award more contracts to minority firms, plan today to unveil a new program that would sharply increase the number of county contracts set aside for minority-owned businesses.

The nine-point program was drawn up by County Council Chairwoman Hilda R. Pemberton and County Executive Parris Glendening after months of criticism by black elected officials and business leaders, who have cited the county government's failure to meet its goal of awarding 30 percent of county contracts to minority firms.

Because of shortcomings in the county's minority business program, the critics have contended, the county's current economic development boom is bypassing the black community.

Minority business leaders who have seen the proposal, which would set aside some construction and other contracts for minority firms and would revamp the county's 2 1/2-year-old minority business program, said that they welcomed it and that it resolves many key issues, although they added that more could be done.

"This is a good framework," said Ralph Clark, who was chairman of the Minority Procurement Advisory Committee, a recently disbanded board that oversaw monitoring of the county's minority business program for the past two years. "If it is properly implemented, monitored and the certification procedures are adhered to, it will be a definite improvement over what we have. We feel it will bring us a little bit closer to reality."

The proposal signals a reversal for Glendening, who has said he is philosophically opposed to sheltering county contracts from normal competitive bidding practices and in 1984 resisted attempts by black political and business leaders to include more than a narrow set-aside provision in the current county minority procurement program.

But in a county whose population is nearly 50 percent black, Glendening, a strong political ally of county minorities, has come under increasing pressure to set up a program to ensure that blacks get a larger share of the funds -- about $90 million annually -- allotted in county and agency contracts.

In the view of many black elected officials, business leaders and community activists, economic development will be the paramount issue in the black community in the 1988 and 1990 elections. Already there is talk of stepping up pressure on school board officials, who only recently met the school system's 10 percent goal for minority procurement. Also, minority business advocates want county officials to persuade private developers to retain more minority companies for nongovernment projects.

With 5,762 black-owned businesses, the county has the sixth-largest number of black-owned firms in the country, according to census data. A total of 1,100 to 1,300 black-owned businesses in the Washington and Baltimore areas have been certified by county officials as capable of supplying goods and services for the county government. Officials say that 20 percent of county contracts went to minority firms in the past fiscal year.

The far-reaching proposal, expected to be approved by the County Council after debate and further modifications, would radically alter the way the county does business with minority companies. Under a plan adopted in 1984, the county awards bonus points during the bidding process to minority-owned businesses and to companies with significant minority participation, such as white-owned firms that employ black or Hispanic subcontractors.

Also, the county created an aggressive program to locate and certify minority companies and to train minority business owners in bidding on government contracts. Contracts worth $5,000 or less -- such as those for janitorial services and trash hauling -- were set aside for minority companies.

County officials declined to comment on the new program before today's planned announcement, which is aimed in part at heading off criticism from black community groups working on their own minority business proposals. But sources familiar with the package said it would set aside a greater number of contracts, including certain construction and procurement awards, for bidding only by minority companies. The nonmandatory 30 percent goal would not change, sources said, but it would be looked at as a floor, not a ceiling.

Performance in purchasing goods and services from minority companies would become a factor in evaluations of department heads and supervisors. A community commission would be set up to oversee the county's performance and to police the program.

Dennis C. Brownlee, the administrator of the county's Minority Business Enterprise Office, now an agency of the county purchasing department, would be moved up to Glendening's staff to give the minority office more weight in dealing with county departments and agencies.

"We've been asking for that for two years," Clark said. "Being under the purchasing agent rendered {Brownlee} ineffective."

The final details of the proposal are to be worked out at an 8:30 a.m. meeting today among county officials and minority business advocates who helped draft the plan.

The proposal already has encountered criticism from black activists who say it does not go far enough and are working on a separate proposal, now in its final stages. They are pushing for county officials to mandate by law that 37 percent of county contracts go to minority companies.

"I don't see any teeth" in the Pemberton-Glendening proposal, said John Spearmon, a spokesman for the local Coalition for Black Economic Development, which represents the county's chapter of the NAACP, the local branch of the National Business League and the Black Democratic Council, a Prince George's political group. "It doesn't seem to address the true issue. That is: Minorities have been denied the opportunity to participate in the full economic process.

"Goals are great," he said. "But if it is mandated, the various entities will use their own creativity to reach that mandate."