Maryland will lose to Michigan in a major consolidation of General Motors Corp.'s parts, warehouse and distribution operations.

GM over the next three years will close seven facilities, including one at Baltimore that now employs 247 people. The company also will modernize and expand eight other parts and distribution centers in a move that will add 250 jobs to the Michigan economy, GM officials said last week.

The Baltimore plant, located near the Baltimore-Washington Parkway in Anne Arundel County, opened in July 1966. Its 1984 payroll totaled $7.8 million.

The $150-million consolidation program is a relatively tiny portion of a corporate reorganization drive GM started last year. One of GM's goals is to cut parts delivery time to its assembly sites and dealers -- a difficult objective under the old system of running the parts and the warehouse and distribution operations as separate divisions, GM officials said.

The seven facilities scheduled for shutdown are either too costly to modernize, or they are redundant in the new distribution scheme, company officials said.

With consolidation, "We will be able to incorporate new state-of-the-art material handling and parts processing technology and take better advantage of transportation systems to further improve service to GM dealers and AC-Delco distributors," said J. Wayne Cagle, general manager of GM Warehousing & Distribution Division. "Everything that can be done will be done to implement the consolidation project in an orderly manner and with concern for the people affected."

James E. Farmer, spokesman for GM's Middle Atlantic region, said that the three-year phase-out should help soften the blow of the facility closings in Baltimore and other affected cities. Normal attrition of workers and displaced employe programs that allow workers to train for new GM jobs should also help, Farmer said. He said GM workers with high seniority also will be eligible to tranfer to other plants within the company's parts distribution system.

In addition to Baltimore, other facilities that will close are located at Buffalo and Bethpage, N.Y., Newark and New Brunswick, N.J., and Philadelphia, where GM has two parts and distribution units.

The clear-cut winners in the consolidation move are facilities at Flint, Pontiac and Drayton Plains, Mich., and Martinsburg, W.Va., where GM will expand is parts and distribution operations.