Del. Wendell H. Phillips (D-Baltimore) announced yesterday that he plans to run for the House of Representatives seat being vacated by retiring Rep. Parren J. Mitchell (D-Md.).

In a statement delivered at the church he heads in Baltimore, Phillips, 50, said that he had been urged by community leaders and by his family to give up his position as chairman of the city's House delegation to try to succeed Mitchell.

Phillips was first elected to represent his West Baltimore district in Annapolis in 1979.

Phillips is expected to face stiff competition in his quest for Mitchell's seat from a crowd that includes lawyer A. Dwight Pettit; City Council member Kweisi Mfume; state Sen. Clarence Mitchell III, Parren Mitchell's nephew, and Augustus Adair, 52, chairman of the political science department at Morgan State University.

Phillips said yesterday that he had not asked Mitchell for his endorsement. Mitchell, who announced his retirement last month, has so far declined to endorse a candidate for his seat.

Endorsements, Phillips said, may not determine who wins in Baltimore's 7th District, a predominantly black area that has some of the city's poorest neighborhoods. "The community is more sophisticated in voting than folks give them credit for," he said. "There's too much at stake to let all that Parren's done go down the tubes."

Phillips, pastor of the Heritage United Church of Christ in northwest Baltimore, has earned a reputation as an advocate for the poor who has consistently sponsored legislation to abolish capital punishment. Until last year, his relationship with Baltimore Mayor William Donald Schaefer was rocky, but during the last year he has toned down his criticism of the Schaefer administration to win support for city causes in the legislature.