The Gill Group, the Beltsville-based distributor of food service equipment, has broken ground for a 34,000-square-foot production facility in Baltimore's Park Circle Industrial Park at 2900 Druid Park Drive. Completion of the project is scheduled for December, with an initial work force of about 50.

The Gill Group also has offices in Greenbelt, Baltimore, San Francisco, Phoenix and West Germany.

Recent developments in commercial realty in the Washington metropolitan area:

* Ma/Comm Linkabit Inc., a telecommunications firm, has leased about 43,000 square feet at 8617 Westwood Drive in Fairfax. The aggregate rental value of the long-term lease is about $8 million.

* ,300 square feet at 6601 Little River Turnpike in Annandale. The aggregate rental value of the long-term lease is about $230,000.

* Illinois Bell has leased about 6,000 square feet at 1050 Connecticut Ave. NW. The aggregate rental value of the lease is about $2 million.

* The Cox Enterprises publishing firm has leased about 8,000 square feet at 2000 Pennsylvania Ave. NW. The aggregate rental value of the lease is about $2.3 million.

* General Foods Corp. has leased 2,600 square feet at 1710 Rhode Island Ave. NW. Reserve City Bankers has leased about 2,600 square feet of space at the same address. The aggregate rental value of the two leases is about $650,000 each.

* The Washington Center, nonprofit educational consultants, has leased about 6,000 square feet at 1101 14th St. NW. The aggregate rental value of the lease is about $600,000.

* The law firm of Kerns and Klimek has leased about 5,000 square feet at 1815 H St. NW. The aggregate value of the lease is about $850,000.

* C & P Telephone has leased about 5,000 square feet at 5454 Wisconsin Ave. in Bethesda.