As a group of Baltimore businessmen met with the club owner yesterday, the Baltimore Orioles announced a 1978 operating loss of $234,141, coupled with a 12 percent drop in attendance.

The loss was more than double that in 1976 and would have represented the third consecutive year of losses had the Orioles not had a windfall profit in 1977 from American League expansion.

The figures were contained in a report to the Securities and Exchange Commission and in letters to club stockholders who were told they had lost $1.15 per share, compared to the $2.85 per share they earned in 1977.

Despite the bleak financial news, the Baltimore group met with Jerold C. Hoffberger, Oriole principal owner, to pursue talks aimed at buying the club to keep it in Baltimore.

The group is trying to raise $12 million to match an offer reportedly made by former Treasury Secretary William E. Simon who the group believes would move the club to Washington.

Members of the Baltimore group refused to say what had transpired during their afternoon meeting with Hoffberger, with one member explaining that Hoffberger will not talk to them if they talk to the press.

If the group is successful in raising the $12 million, it could cost them more than $7.5 million to run the operation this season, if costs continue to escalate as they did over the past year.

Total operating costs for the 1978 season were just over $7.5 million, compared to $6.8 million in 1977. The largest increase in 1978 was in what the club calls its "playing" category that encompasses salaries, transportation, lodging, insurance and retirement benefits.

That category jumped 11 percent, from almost $3.2 million to $3.5 million. Player salaries accounted for 8 percent of the increase, according to Oriole Vice President Joseph P. Hamper Jr. Player salaries increased from just over $2 million in 1977 to $2.3 million in 1978.

At the same time, attendance dropped to just barely over 1 million persons in 1978 from the nearly 1.2 million in 1977, the second-highest gate in club history.

"It's almost impossible in today's conditions to put down a figure and say you're not going to go beyond it," said General Manager Hank Peters, citing inflation and ever-rising player salaries.

Peters said the Orioles are exploring new sources of revenue, in addition to the increased income expected from broadcasting contracts and a 25-cent increase in ticket prices.

Season-ticket sales are lagging behind last year, Peters said, "because of the unsettled status of the club."