Lockheed Corp. announced yesterday that it will phase out production of its L-1011 TriStar commercial jet aircraft.

The end of the L-1011 assembly line will mean that Lockheed won't have a commercial airliner to sell, leaving the commercial jet aircraft market to the other two major U.S. commercial aircraft manufacturers: Boeing and McDonnell Douglas.

Lockheed said its decision was based on a lack of orders and an inability to project with confidence an upturn in the commercial aircraft market. "Despite an intensive marketing effort, the existing backlog of orders is not enough to sustain continued production at an economically justifiable level," Lockheed Chairman Roy A. Anderson said yesterday. While industry forecasts and population and travel trends support expectations of an "ultimate increased need" for wide-bodied aircraft such as the TriStar, "the timing and adequacy of a market upturn is extremely uncertain," he said.

"The financial consequences of attempting to sustain production at a reduced rate in anticipation of such an upturn leave us no other choice but to begin now to phase the program out in an orderly manner," he said.

Anderson said the last of the L-1011s now on firm order will be delivered in 1984. He said Lockheed would continue to work with customers to fulfill additional requirements.