Prince George's County State's Attorney Alex Williams has infuriated fellow political leaders on a countywide ticket by giving substantial campaign contributions to black candidates challenging members of the political team.

Williams, who four years ago became the first black politican elected to a top countywide office, this year is part of the predominantly white slate with Democratic county officials and state legislators. At the same time, he has broken traditional slate etiquette by contributing thousands of dollars to candidates challenging other incumbents in the Sept. 11 primary.

Sen. Thomas P. O'Reilly, who is coordinating slate activities, said he is "personally offended" by Williams's donations to opposing candidates.

"It's been my understanding that if you run on the team, you support the team and you don't support opponents of the team," O'Reilly said. "It's about loyalty. If you don't have that in politics, what do you have?"

Williams, who is unopposed for reelection in the primary, offered no apologies. He said his strategy was to help all, in hopes he would receive help from all in his general election campaign.

"To the extent that it's going to cause some problems, well, it was going to cause problems either way," Williams said. "We decided it would be more harmful to remain on the sideline. I don't believe I'm in a position to slight these people, particularly black candidates who asked me for donations."

Several county political leaders expressed displeasure with Williams, but stopped short of predicting that his contributions would cause him difficulty in the general election against former state's attorney Arthur A. "Bud" Marshall Jr. With the help of top county officials, Williams defeated Marshall in the 1986 Democratic primary, and Marshall switched to the Republican Party this year to create a return match.

"I don't think it's fatal, but it took the enthusiasm out of places where Alex could use help in the fall," said one top Democrat, noting that the incumbents could decide to sit out the general election campaign and decline to work for Williams.

Almost since his election, Williams has been criticized by some black leaders for not using his position to become the dominant force around which the divided black political community could rally. At a time when the county population is about 50 percent black, Williams was chided for not doing more to increase the number of black officeholders.

Williams said yesterday that he thinks the contributions address, in part, such criticism.

"This demonstrates that I don't blindly go with the ticket, rubber-stamping everything that the ticket does," Williams said.

According to campaign reports filed last week with the state, Williams had collected $116,500 in contributions and had $80,000 in the bank. From his total, he transferred $3,000 to Del. Gloria Lawlah, 10 percent of all the money she had amassed for her attempt to unseat Sen. Frank J. Komenda in southern Prince George's County's 26th District.

Komenda, who shares a spot on the countywide slate with Williams, chose his words carefully when asked for reaction. "This is kind of a unique experience," Komenda said. "Alex says he needs to keep everybody as his friend, that he needs {primary} winners and losers with him in the general election."

Williams also transferred $6,000 to a separate fund, the Black Citizens Action Alliance for Prince George's County Political Action Committee. The committee, in turn, gave $2,500 to Democrat C. Anthony Muse, a minister who is challenging three incumbent delegates in the 27th District. The PAC, formed in late June, also sent contributions of $1,500 each to County Council candidate Linwood Jones in the 6th Councilmanic District and House of Delegates candidate C. Hope Brown in the 22nd Legislative District.

Jack B. Johnson, treasurer of Citizens for Alex Williams, confirmed that Williams asked the alliance to donate money to Muse, but he said the PAC decided the other contributions on its own. Johnson said Citizens for Alex Williams also has given $500 to former representative Charles C. Diggs Jr., who heads a three-member slate of delegate candidates in the 26th District.

Senate President Thomas V. Mike Miller Jr., a principal Democratic leader in the county, noted that Williams's share of the cost of the campaign for the slate is $15,000.

County Executive Parris N. Glendening also declined to criticize Williams. "Each person has to make his own decisions," Glendening said, "knowing full well that everyone else is going to know."

Said Williams: "This kind of thing is done all the time, but some people don't have the guts to do it openly, or they don't have the financial backing to do it."