By agreeing to sponsor the prestigious Washington Star International tennis tournament for the next three years, D.C. National Bank has assured the continuation of a major recreational program for economically disadvantaged youth in the area.

The tournament, which is owned by the Washington Area Tennis Patrons Foundation Inc., is a major source of funds for tennis day damps and a combination of educational and recreational programs.

The foundation also provides travel assistance for promising young tennis players and contributes to some city recreation programs.

In each of the past two years, the foundation put just under $100,000 in programs for Washington-area youngsters, most of them District residents.

With the demise of The Washington Star last year, the future of the tennis tournament was uncertain until D.C. National concluded that here was an opportunity for the bank to increase its involvement in community affairs.

To be sure, the bank's decision to sponsor the tournament, which will be renamed the D.C. National Bank Tennis Classic, is rooted in motives that aren't exclusively altruistic.

True, D.C. National will underwrite 80 percent of the purses through its contribution of $675,000 over three years, but its sponsorship of the tournament, though expensive, is "cost effective" in attracting business, acknowledged Thomas S. Condit, the bank's president.

Indeed, Condit said, sponsorship of the tourney "has to be very beneficial to us over a long period of time."

In essence, D.C. National hopes its association with the tournament will enhance its image among District banks and win customers. Although D.C. National is the District's seventh largest bank and has had impressive growth over the part four years, it suffers from a lack of recognition, Condit says.

While most banks rely a good deal on advertising to attract business, D.C. National doesn't consider it the best vehicle for offering its products to its target market -- commercial customers.

"We don't do too much advertising because advertising is used particularly to go after retail and consumer business," Condit explained.

While it does have a fair amount of the retail banking market shared by the District's medium-sized banks, D.C. National's customers that provide that portion of its business generally are employes of its commercial clients. In any event, the bank doesn't rely on advertising to attract either commercial or retail customers.

"We've grown through referrals and it's been good, but there are still a lot of people who don't know who we are," Condit said.

Indeed, D.C. National has tried for several years to develop a strategy that would "let people know who we are," Condit disclosed.

Sponsoring the tennis tournament is perhaps the most effective vehicle for fulfilling that need, he said, because it attracts the types of customers the bank wants to reach -- "professionals, high-education levels, high-income levels," as Condit described them.

"That's the market we want to reach, and a very large portion of that market is completely unaware that we exist," he said. "There's not the level of market awareness of us... that we want."

A major reason for that, he added, is that there are so many banks in the District with similar names, leading to confusion.

On the other hand, potential clients that D.C. National hopes to attract are aware of the Star tennis tournament, Condit reasoned.

"And to just have on a sports page and various other media the D.C. National Bank Tennis Classic is going to make people aware that we are an important enough bank to sponsor this important event."

While the tennis tournament is a highly visible example of D.C. National's involvement in the community, it is by no means a one-shot deal, Condit emphasized.

"We have done a lot of work where we have sponsored things, but there has never been anything like this."

At the same time, Condit noted, D.C. National has a strong lending record in the District. Most District firms, he added, are medium-sized businesses and "that's our market."

The decision to concentrate on the commercial sector apparently has worked well for D.C. National. It reported total assets of $64 million and earnings of $450,000 at the end of 1977. At the end of 1981, assets had risen to $157 million and earnings were $2.2 million.

The shift in emphasis to the commercial customer was a decision made four years ago "from hindsight," Condit volunteered. "The opportunity to do consumer banking is limited and so competitive.

"Our basic strategy is to increase our penetration of [the commercial banking market] no matter what happens to banking laws."

And what if changes in banking regulations permit interstate banking? Would D.C. National, through its holding company, D.C. National Bancorp Inc., pursue acquisitions or branches across state lines? Condit says not.

The bank might be interested, he said, in opening business offices in Friendship Heights, Crystal City or Tysons Corner, but only because they could generate corporate loans from customers in those areas.