The Watergate Hotel, two office buildings, a shopping mall and a boutique area in the nationally known complex in Foggy Bottom have been sold for about $49 million.

Nicolas M. Salgo, who has been involved in both the connection and the construction of the total $100 million-plus complex that also includes 740 individually owned co-operative apartments in three buildings, said he and Continential Illinois Properties, a Los Angeles-based real estate investment trust, are the new owners. He said the purchase price was $10 million and assumption of an existing first mortgage of $39 million.

The seller was Watergate Improvements, Inc!, a subsidiary of the financially troubled Societa Immobilaire Generale.

Salgo, a Hungarian who was raised in France, said he will continue an active interest in the Watergate complex that was started here in the early 1960s on a 10-acre site of a former gas plan that had been abandoned and sold by the Washington Gas Light Co. The vacant site had gone undeveloped for a number of years before being purchased by SGI, which represented investment interests in Rome and other European capitals.

The recent property exchange, as outlined by Salgo, will not involve any changes in management of 260-room hotel, the Watergate 2600 office building and the Watergate [WORD ILLEGIBLE] office building. The latter have a total of nearly [WORD ILLEGIBLE] square feet of office space. The Watergate break'in to Democratic party headquarters occurred in the 2600 building on Virginia Ave. NW.

Also involved in the transaction are Watergate mull arcade and 200,000 square feet of shopping area in the center of Watergate and the Lc Champs boutique area in Watergate 600.

Continental Illnois Properties, which now has a major ownership position with Salgo, is the real estate arm of the Continental Bank of Chicago.

The ground under the entire Watergate complex, located adjacent to the Kennedy Center and the Columbia Plaza apartment complex owned by John Hancock Life Insurance Co, which also provided the original mortgage financing for the entire project.