Ivanhoe Donaldson, a former top aide to Mayor Marion Barry, probably will step down next month as chairman of the D.C. Democratic State Committee after serving one term, according to sources.

Donaldson, an executive with the E.F. Hutton Co. and the chief architect of Barry's rise to political power, has indicated to friends that he may give up the post to devote more time to his business affairs and tend to his legal problems. He is the target of a far-ranging federal grand jury investigation into his past government and business activities.

Also, Sharon Pratt Dixon said this week she probably will relinquish her post as D.C. Democratic National Committeewoman, throwing open another key local party post. Dixon, an executive with the Potomac Electric Power Co., was elected treasurer of the Democratic National Committee in January, and says it wouldn't make sense for her to continue to hold both party positions.

"My inclination would be to step down . . . to give D.C. another seat on the Democratic National Committee," Dixon said.

Donaldson will reveal his decision on June 6, when the state committee meets to elect new officers for the coming year.

"He's too busy with his work with E.F. Hutton and he's always out of town," a source close to Donaldson said this week. "With these other legal problems and with the mayor's reelection campaign heating up, it might be wiser for Donaldson not to be the party chair than to be chair."

Another source said yesterday that Barry has told some local Democrats that Donaldson has decided to step down in part because of the federal investigation.

Donaldson, who was unavailable for comment yesterday, told a reporter recently that he hadn't "focused" yet on his plans. Daria P. Winter, vice chairman of the local party, said this week that Donaldson has not discussed his future with other members of the state committee.

"As far as I'm concerned, I hope he's running," Winter said. "I think pretty much everyone is waiting for his announcement."

Linda Grigsby, chairwoman of the Ward 2 Democrats and a member of the state committee, said that Donaldson has been a popular chairman and that she and other members would encourage him to seek another term.

"We have progressed and he has been a strong, able leader," she said. "Basically, our Ward 2 delegation hasn't had any problems with the leadership of Mr. Donaldson. We feel the committee has been moving progressively ahead."

The names of at least five potential candidates for party chairman surfaced recently, according to party officials and a Democratic member of the City Council, further fueling speculation that Donaldson has decided to step down.

They include Winter; Joslyn N. Williams, president of the AFL-CIO's Metropolitan Washington Council; James M. Christian and Vincent H. Cohen, both Washington lawyers; and Larry Weston, executive director of the Metropolitan Washington Planning and Housing Association.

Donaldson swept to an impressive 2-to-1 victory a year ago over the incumbent, Theodis R. (Ted) Gay, after a bitter campaign in which Gay supporters complained about the tactics of the Donaldson-Barry forces. Gay warned party members that Donaldson would transform the local party into "an organization that serves the political ambitions and interests of a select few."

But Donaldson gained the respect and support of most state committee members with a businesslike but accommodating style and a knack for party organization and fund-raising.

The state committee's annual Kennedys-King Day dinner this year drew a record 1,100 guests and netted the party about $31,000, according to party officials.

Bernard Demczuk, a labor official and the state committee's finance chairman, said the party will make a big push this year for City Council enactment of legislation allowing D.C. income taxpayers to check off a $1 contribution to the local party of their choice. Such legislation potentially could generate more than $200,000 a year for the local Democratic Party, he said.

Williams, the AFL-CIO leader, said yesterday that Donaldson has proven to be a "good nuts-and-bolts" leader who has brought some much-needed discipline to the party.

"He straightened out the ward and precinct operations and people just feel comfortable with him -- including people who opposed him the first time around," Williams said. "This reputation that he was going to get back at people who disagreed with him and the mayor wasn't right. On the contrary, he helped people who opposed him . . . . He used the carrot-and-stick approach."