Seventeen bishops from two predominantly black Methodist denominations met here last weekend to begin negotiating a merger and, in one of their first acts, passed a resolution supporting joint services and activities among neighboring congregations.

The proposed union of the African Methodist Episcopal Zion Church and the Christian Methodist Episcopal Church, would result in a combined membership of approximately 1.9 million in the United States and 2.6 million worldwide. The merger would take place gradually, with completion by 1988, according to church spokesmen.

"We've been working 100 years to merge with other denominations," said Bishop Nathaniel Linsey, bishop of the East Coast CME district. But a suitable partner did not emerge until last year when representatives of the AME Zion Church, with its 1.8 million members worldwide, approved the plan at their annual convention.

"Our doctrines are pretty much the same, we cover the same territory and we serve the same people," said Bishop William M. Smith of Mobile, Ala., senior bishop of the AME Zion Church. "The differences we have in polity church government can easily be adjusted," he said.

The merger would save "millions of dollars" by eliminating duplication of seminaries, overseas mission work, publishing and administration, according to Smith.

Smith also expects the union to increase the denominations' political impact. "One thing this country respects is numbers," Smith said. "I think perhaps in the past they members of the two denominations haven't been heard as much as they should have been."

During the next year, a commission made up of 48 lay and clergy of both denominations will meet frequently to find a name for the new denomination and to iron out sensitive issues, such as redefining bishops' territories, which now overlap.

"You can bet we have a whole lot of knotty problems to work out," Smith said.

Roots of the AME Zion Church were set down in 1796 when black members of the Methodist Church withdrew to form a separate denomination.

The CME Church was formed in 1870 when black members of the Methodist Episcopal Church, South, withdrew to form the Colored Methodist Episcopal Church. The name was changed to the Christian Methodist Episcopal Church in 1954.

Both the CME and AME Zion churches, along with the other black Methodist denomination, the African Methodist Episcopal Church, participate in the Consultation on Church Union, the effort to unite nearly a dozen of the nation's leading churches into one Protestant church.