The Baltimore Orioles, coming off one of their worst years financially, are hoping to escape a red-inked bottom line in 1978 by luring as many baseball-hungry Washington-area fans as possible.

Letters going out to the club's stockholders this week show that the Orioles made a profit of $580,788 in 1977 - but only because the Orioles received one-time-only income from the American League's expansion, an expansion the Orioles opposed.

As a result of the league's expansion into Toronto and Seattle, the Orioles picked up $875,000 through the sale of five players. Without that income, the club would have had a $43,846 deficit.

It would have been the second year the club showed an operating loss since the Orioles came up $102,531 short in 1976.

The Orioles' 1977 profit was second only to the $643,307 they made in 1954, their first year in Baltimore.

What is, perhaps most disheartening about their 1977 season is that the Orioles drew just under 1.2 million fans to Memorial Stadium, their second-highest attendance. In 1966, when they were building toward a World Series victory, the Orioles drew just over 1.2 million.

General manager Hank Peters is concerned about what the future holds if their second-highest attendance in history was not enough to give the club a profit without the expansion income.

"The question is, can you continue to get by if you don't draw more than 1.2 million people?" Peters said. "Based on our current revenue (projections) - including TV - we're not going to crack it.

"It might be a fantastic year (on the field), but it won't be fantastic enough to break (the attendance figure)."

Peters declined to release full financial data until the stockholders received it, but he said that 40 percent of the club's income goes toward salaries, another $320,000 toward retirement benefits and $1.6 million toward player development - "the bread and butter of the Orioles."

Inflation and "rapidly escalating" player salaries have been a burden to the Orioles as they have to other clubs. Operating costs went up $550,000 between 1976 and 1977 and all but $50,000 of that was for salaries, Peters said.

The Orioles have spent little in the free-agent market, picking up only Billy Smith and Elrod Hendricks, with the latter devoting most of his time to coaching.

The Orioles' Al Bumbry, Lee May and Pat Kelly are eligible to become free agents at the end of the season - a situation neither Peters nor board chairman Jerold G. Hoffberger will discuss.

Knowing there will be a certain fixed income in 1978, the Orioles are hoping to end up in the black by increasing attendance and revenue from other sources - which brings them to Washington.

The Orioles are in the last year of their existing radio and television contracts and are hoping also to pick up outlets in Washington, where a survey they commissioned showed 10.1 percent of their attendance came from last summer.

A breakdown of the attendance by business manager Al Harazin showed these attendances, in percentages D.C. (2.3), Prince George's (3.1), Montgomery (2.0) and Northern Virginia (3.7).

"We do have to increase attendance Peters said. The vast, untapped market would be your end (Washington area) of the market. We've had a lot of interest shown from your area in terms of fan mail and media coverage - which is probably due to the quality of the team.

"We would like to appeal to these people and say that you've got baseball at your doorstep (Baltimore). This is not a move on our part to annex Washington."

Ever since the Washington Senators left for Texas after the 1971 season, there have been informal attempts in baseball circles to have Washington considered part of Baltimore's territory. There have also been plans - currently dead - to have the Orioles play some games in RFK Stadium.

"I have nothing to say," Hoffberger responded when asked if Baltimore looked upon Washington as its territory. "I'll just say that we're trying to attract new fans and every fan we can get into the ball park, the better."