It was over dinner in a little Italian restaurant in Baltimore two Sundays ago that Henry Bosz popped the question: would his dinner partner, Maria, take a job as his personal secretary?

A simple, straightforward situation - but there were a few underlying complications. For one thing, Henry Bosz, as head of Maryland's Department of Personnel, is the man who stands behind the administration of the state's personnel rules and regulations.

For another, his dinner partner Maria is also his wife.

Maryland has no nepotism rule forbidding a state government official from hiring a wife or relative as his secretary? At the same time, there are no civil service constraints or requirements that applicants take competitive tests for top clerical jobs.

So, with no legal barriers in the way, Mrs. Bosz considered the offer for a day and then accepted.

Unlike most accounts of public officials hiring their relatives, this one wasn't made public by resourceful reporters or high powered governmental probes. The man who made it public was Bosz, and he did it by releasing a press statement earlier this week.

"I was apprehensive," Bosz said in explaining his reasons for making the hiring of a $12,000-a-year secretary the subject of a statewide press release. "Not to the extent that I worried about bureaucratic acceptance of the decision . . . but about public acceptance."

"I wanted to lay out the whole thing," Bosz said yesterday.

Mrs. Bosz is no stranger to state government: She is now, a $12,000-a-year secretary to the Maryland state school superintendant. She has worked for the state for 26 years, several years longer than her husband.

And, as both pointed out in interviews yesterday, they met while they worked at the Department of Mental Hygiene in the late 1950s and became an "office romance."

"She has better than two decades of experience working at top-level jobs in the state," Bosz said yesterday. "She has dealt with a number of the same people I have to deal with, so there'd be a minimum of adjustment for her.

"I think . . . I know that I'm getting a trained, top-level secretary," he concluded.

Mrs. Bosz said, however, that she "had mized emotions about this." The main reason was the circumstances under which the job became open: her husband's secretary for the last eight years, Eleanore Scott, had died suddenly of a previously undiagnosed case of acute leukemia.

Since Miss Scott had been coming to work daily until three days before her death, Bosz said he had no warning and no chance to scout around for a replacement for the woman who had been "the perfect secretary."

He received a number of phone calls of condolence, he said, some from women who dropped not-so-veiled hints about their interest in the newly open job of Administrative Aide II in his office.

The he thought of his wife. Immediately, he started calling longtime friends to see what reaction the appointment might bring. They advissed him to go ahead.

"I've been in the Department of Education for 12 1/2 years," Mrs. Bosz said. "This was something new." As for the raised eyebrows ever since henry became head of personnel for the state. That's nothing new."

She paused, then said with more than a tough of humor, "The marriage has been very smooth up to this point . . . I hope it stays that way."