Jesse L. Jackson was endorsed yesterday by more than three dozen black political leaders and a major Black Muslim minister in Chicago as his presidential campaign appears to be stripping support from Mayor Harold Washington's favorite-son candidacy.

Washington has indicated that he will announce a "preference" for Jackson as a presidential candidate, but he is expected to urge Illinois voters to support his favorite son slates in predominantly black congressional districts in the south and west sides of Chicago in the March 20 primary.

Louis Farrakhan, leader of the Nation of Islam, a national Muslim group, registered to vote for the first time in his life accompanied by several hundred followers in a well-orchestrated gesture of support for Jackson. Farrakhan's registration is a major break with Muslim preachings that blacks not participate in a political process controlled by what they call white oppressors.

But yesterday, before television cameras and a huge local press corps, Farrakhan registered and said, "I as a Muslim urge all black people to register and vote and back this candidate . . . . I have registered at 50 years of age with a sober mind, a clear conscience and with deep humility . . . . I would rather see young blacks register to vote and march to the polls to unseat candidates undeserving of power. We have no choice between violence and voting."

Farrakhan and Jackson later rallied a crowd of several hundred in a City Hall lobby to preach the same message, and Farrakhan said that hundreds of thousands of new black voters would be registered on Jackson's behalf by Election Day.

More than three dozen black aldermen, state committeemen and ward leaders were among those supporting Jackson.