The Reverend Al Sharpton will call on black political leaders in Brooklyn to unite behind a single black candidate in the 11th congressional district but not specify which candidates should drop out of the crowded race, a source close to Mr. Sharpton said.

The call from Mr. Sharpton will be made this Saturday at the Black Brooklyn Empowerment Convention, where he is the keynote speaker.

Running to replace Major Owens, who is retiring from congress after 24 years are Council Member Yvette Clarke, state Senator Carl Andrews, and Mr. Owens’s son, Christopher, who are black. Also in the race is Council Member David Yassky, who is Jewish.

Empowering African-American voters by reducing the field of black candidates is a dilemma that not many political leaders are rushing to embrace. On Monday, Mr. Owens called on the chairman of the Democratic National Committee, Howard Dean, and the chairman of the New York State Democratic Committee, Herman “Denny” Farrell, to support the concept of “power sharing” and state that a black candidate should be elected to represent the district.

“We are confident that whichever Democrat is nominated will be a great representative for the people of this district,” a spokesman for Mr. Dean, Damien LaVera, told The New York Sun. Mr. Farrell has declined to comment on the race. The Kings County Democratic leader, Assemblyman Vito Lopez, did not return messages left with his spokeswoman and his Albany office.

“All three cannot remain and that seat remain a black seat,” a convention organizer, Tyquana Henderson, said.

“History shows that, for the most part, white voters don’t cross over and vote for black candidates,” Council Member Albert Vann said. “With that history and other factors, it is very probable that if two or three black candidates run, then Yassky could win. That’s the risk we take.” Mr. Vann is also a convention organizer. The dean of the New York congressional delegation, Rep. Charles Rangel of Harlem, said reducing the field of candidates does not conflict with the goal of empowering voters.

“Of course the more black candidates you have the easier it is for a non-black candidate to win,” Mr. Rangel told the Sun. “And all this stuff about giving voters the most choice, that’s ridiculous. We don’t have that anywhere in a primary, where you want to bring in more black candidates into a primary for purposes of choice.”

When asked whether there was an urgency to reduce the number of black candidates in the race, Mr. Vann said, “Of course there is.”