Shoppers and retailers can look forward to more store space along M Street in Georgetown come the spring of 1987, says Gregg O. Dawley, assistant vice president for Coldwell Banker Commercial Group Inc.

Last month, Coldwell Banker Commercial Real Estate Services began the second phase of construction on Georgetown Park. The 118,000 square feet of additional retail space will provide room for 60 more shops, according to Dawley.

The project will include building an additional four-story building, renovating the existing Market House and landscaping several outdoor areas. Upon completion, Georgetown Park will have a floor area of 316,000 square feet and will occupy the M Street block between Wisconsin Avenue and Potomac Street.

"Interest in expansion has been strong, particularly among retailers that we have been unable to accommodate in phase I," said Dawley. "The existing center has averaged 98 percent occupancy since 1982, and sales in 1985 approached $400-per-square-foot."

The added shopping mall will be joined to the original Georgetown Park by an outside walkway on the east and to the renovated Market House by an outdoor cafe on the west. It was designed by Stinson-Capelli Architects and will feature a four-level atrium, a fountain court and skylights.

The Market House will be converted to a gourmet food hall providing 13,000 square feet of vending space for local produce, bakery items, meats and cheeses. The space is intended to be leased to a master vendor.

The original Georgetown Park was the result of a joint venture between Western Development Co. and The Donohoe Cos. In July 1982, Coldwell Banker joined the partnership as the managing general partner. Last October, Coldwell Banker purchased total interest in the project and the phase II expansion site. Leasing will be handled by Coldwell Banker.

Other recent developments in commercial realty in the Washington metropolitan area:

*The Department of Education has leased 61,665 square feet from The American Federation of Government Employees at Capitol Place II on 80 F St. NW. The 10-year lease has an aggregate value in excess of $15 million.

*The Neighborhood Reinvestment Corp. has entered a 10-year lease with Prudential Insurance Co. for 28,798 square feet at 1325 G St. NW.

*The Agency for International Development has leased 25,102 square feet from 515 22nd St. Limited Partnership at 515 22nd St. NW. The aggregate lease value is in excess of $2 million.