There's another foreign presence in the city on the Thames. Riggs National Bank last week became the first Washington area bank to open an office in this international financial capital.

The move across the Atlantic is intended to increase Rigg's foreign lending operations, which already account for 40 per cent of its commercial loan business, and expand its participation in the curodollar market.

Peter DuBose, vice president of the international division, said the bank will initially participate in syndicated loans managed by other banks in order to win the contacts and publicity necessary for it to begin arranging its own bilateral loans.

As the 56th American bank with a London office, DuBose said, Riggs will have access to proosed loan packages that it would never hear about in Washington.

It's statues as a representative office, rather than a branch, strictly limits its functions, however. The office cannot transact any business - such as cashing checks - for Washington account holders in London and it cannot generate any income itself. The latter means that proposed loans must referred to Washington for approval.

Its discreet offices, located one flight up in a building next to Mansion House Underground station, are unmarked, but a few account holders - members of the diplomatic corps who are familiar with Riggs from Washington assignments - have sought to open personal accounts. Riggs couldn't comply, unfortunately because of the representative limiyation. The office is staffed by three officers, headed by vice president Peter A. Knowles.

Same Washington area shareholders - while looking forward to higher earnings from increase leanding operations - were less than happy with the festivities arranged for the London opening. One shareholder said the bank has been "covering up" all expense paid to London trips for Riggs' 25 directors and several bank excutives.