Metropolitan Washington's business community yesterday launched its first campaign to promote the city and its suburbs as a premiere international financial center.

Although Washington may not replace London as the center for international financial arrangements or New York as the focus for domestic business credit, "more and more government and inter-government relationships" have created an enviromental for significant growth in international business here, said Riggs National Bank Daniel Calahan.

"I ecpect Washington to be political, economic and financial information centre of the world," Callahan said in an address to 50 U.S. and foreign business and diplomatic officials at Meridian House International.

The Riggs officer said Washington area business leaders would welcome the competition from overseas investors, but he was greeted with a round of laughter when he offered some advice about bank acquisitions.

"If you . . . want to buy a bank, talk to the Fed (The Federal Reserve Board) and pay attention to the Securities and Exchange Commission before moving," he said, in an obvious reference to the current battle for control of Financial General Bank shares Inc., a $2.2 billion Washington bank holding company.

The speakers in yesterday's seminar, arranged by the Metropolitan Washington Board of Trade, included former senator Hugh Scott, American University President and former under secretary of State Joseph J. Sisco, former chief of protocol Henry Catto and Board of Trade President R. Robert Linowas.

As might be expected, all of them adopted the theme that doing business in the Washington area would be as good for foreign companies as for firms based in this country.

But Robert E. Wieczorowski, who has been seeking to develop Washington's international financial stature for several years, said the real significance of yesterday's meeting is that it represented the first open declaration by the local business establishment that the area has much to offer overseas investors.

Kenneth Crosby, vice president here for Merril Lynch, Pierce, Fenner & Smith, said the key attraction is the location in Washington of the headquarters for such international and financing agencies as the World Bank, International Monetary Fund, Export-Import Bank, and Inter-American Development Bank.

The annual volume of loans and aid approved by these organizations annually exceeds $7 billion and is growing, he said, "New York might appreciate the international financial centre here more than we do," Crobsy added.

Manuel A. Castilla of the National Bank of Washisngton said after the formal presentations were completed that business trade must first become established before there will be a growth in international financial activities.

He suggested that Washington develop an international trade fair to attract foreign business and their goods, because the metropolitan industry lacks an industrial base that would attract overseas capital.

Paul Petrus, Washington manager for Mobil Oil Corp, which recently completed plans to move some 1,300 workers to Fairtax County form its New York headquarters, listed proximity to government, ease of transposrtation, communication and the area's labor pool as major attractions for his firm.

A native New Yorker and former resident of Darien, Conn., Petrus said he had been "uneasy" when reasigned here two years ago by Mobil. Now, he said, "they can't move me." Petrus emphasized, in particular, commuting time - noting that future Mobil workers in Fairfax could chose to live 20 minutes away in the country or in a D.C. townhouse, where travel to and from work would be against the path of congestion.

Participants yesterday also saw a new, 10-minute slide presentations prepared with a tape-recorded narration by WRC newsman Jim Hartz. The international promotional campaign is a companion to a Board of Trade program designed to attract U.S. businesses that was launched several years ago.

According to Leo A. Zaly III, who heads a Board of Trade international committee, "This area is in the midst of a business boom that is likely to accelerate and continue for a relatively long period." Board of Trade officials emphasized to their audience that they were seeking investments throughout the area - in D.C. and all the suburban counties and independent communities.