When Howard County Executive Elizabeth Bobo decided to dismiss a popular department head who had worked for the county for more than 25 years, Althea J. O'Connor was there.

It was O'Connor, after all, who had helped the administrator and his staff prepare a review of the department's strengths and weaknesses, a document that would ultimately be used to decide his fate. As news of the firing spread, O'Connor, too, was the one who steadfastly insisted to reporters that there was no more to it than a desire for "a change in leadership." Finally, it was she who shepherded a citizens committee through an exhaustive search for a replacement.

As administrative assistant to the county executive, O'Connor -- who has lived in the same house in Highland for nearly 25 years and goes by the name of "Tee" -- could be expected to play an important role in a fledgling administration. But according to elected officials and staff members, she has brought unprecedented authority to the $45,000-a-year position.

"Tee is carrying major responsibilities and is very much respected throughout the executive's staff," said County Council member Ruth Keeton, whose association with O'Connor stems from their days as active members of the League of Women Voters. "In areas that are critical to the county's future, she is Liz's major partner."

"She has a greater latitude to get involved in substantive policy issues, to speak with the backing of the county executive," agreed Council Chairman C. Vernon Gray.

From controversies over Rte. 100 to public housing and the county's 22-cent property tax increase, O'Connor has been at the center of most recent debates.

When Bobo needed someone to serve on a state task force looking at the explosive issue of school construction funding, O'Connor was the county executive's -- and the governor's -- choice. During the next session of the Maryland General Assembly, she will begin spending two or three days a week serving as the county's unofficial ambassador to Annapolis, a decision that has delighted members of Howard's legislative delegation.

"All the large counties have full-time government liaisons during the session, and I think it's important that Howard County has a person there who's competent, who's informed and credible," said Democratic Sen. Edward J. Kasemeyer.

So vast and various are O'Connor's duties and so visible has her profile been during the last year that more than a few people inside the George Howard government building have commented on the situation, sometimes wondering only half-jokingly if Bobo's right-hand woman isn't really the power behind the throne.

"You can go to meetings and Liz will be there and Tee will be there and someone will ask Liz a question and Tee will give the answer," said one county official.

Bobo acknowledges that O'Connor is a key player in her administration. "I see where some people might be threatened that I let a staff person have as much visibility as Tee does," Bobo said. "She is extremely competent and does her job very well . . . . In addition, she's a very strong personality. What's the point in surrounding yourself with weak people? . . . To the people who work here, there's no doubt who's in charge and who makes decisions."

All this seems vaguely embarrassing, if inaccurate, to a 52-year-old mother of six and a Terrapins fan who only 12 years ago was entering the job market as a professional for the first time. True, O'Connor explained in a slow, deliberate voice that is part Maryland, part her native small-town Pennsylvania, she often attends meetings on Bobo's behalf during her 12-hour workdays. Yes, the executive does invest in her a tremendous amount of responsibility. But the decisions, she said, are always Bobo's.

"Sometimes people in meeting with {Bobo} don't understand the complete trust relationship she has with staff. They may be a little uncomfortable to explain to one of us what they want to talk to her about until they can be assured it works well that way," O'Connor said of her boss. "I would hope that people would realize, especially if they have some concern, that as a staff person I work for Liz and if I'm speaking for her, it's because I know what she wants me to say . . . sometimes down to the exact wording."

Whether or not they agree with her high profile, almost everyone who knows O'Connor acknowledges that she is an asset to the county government.

"She's the kind every large operation needs -- someone who can pull all the pieces together," said Paul Steves, who retired as the county's management services administrator in December.

Thomas G. Harris Jr., who left his job as head of planning and zoning about six months into Bobo's term, also had nothing but praise for O'Connor. "She made sure that meetings got scheduled between the various departments and the executive as quickly as possible and really kept things going," Harris said. "In terms of follow-through, I found her extremely responsive."

O'Connor's involvement in county issues began in 1970, when she and her husband Patrick, a retired National Security Agency employe, joined the local League of Women Voters. Although she had graduated with a degree in political science from American University in 1957, O'Connor had been devoting much of her time to her family and church.

After she completed a paralegal course at George Washington University, she was hired as a legislative assistant to the county council.

"One of the things I always liked about working with Tee on the council was she was very opinionated, but she was also very careful in thinking through both sides of an issue," said Del. Virginia Thomas, who was on the council that hired O'Connor.

She applied to be executive secretary to the council in 1979, but was passed over for another candidate with more experience. O'Connor then went to work as the assistant director of the Maryland Association of Counties, an organization that provides information and lobbying services for the state's 24 jurisdictions. When her boss resigned, O'Connor was named to the top job.

"I remember people telling me, 'The toughest questions you are going to face relate to your family,' " O'Connor said. "So I decided to try to make my being a mother of six children a plus instead of a minus. When they asked me why I thought I might be well-qualified to be executive director, I said that one of the things you have to do is be able to juggle a lot of balls at one time. Then I mentioned one year when we had four different kids on four different ball teams and my husband was refereeing two teams and somehow I had to manage to get everyone fed and at the right place at the right time."

While others with limited experience might have been daunted by the wheeling and dealing of the political process, O'Connor seemed to thrive in it, despite the daily commute to and from Annapolis, her husband said.

"Tee can read very quickly and is very good at putting what she reads into writing. When you have to go through some 300-plus bills in a session, that helps," Patrick O'Connor said. "She can also talk to almost anyone about any subject, and these are skills that lend themselves to politics."

She left the county organization in 1985, and then Bobo asked her to join her campaign for county executive. O'Connor, hungry to express her sentiments after years of having to assume a nonpartisan posture, agreed. Two days after Bobo won in a landslide last November, the new executive immediately put her campaign coordinator in charge of managing her transition.

During the first few months, it seemed that one could hardly go to a public event without finding O'Connor standing by Bobo's side. They interviewed prospective hires over breakfast, took lunch in Bobo's office, or, on the days when they had meetings in Annapolis, ate sandwiches in the car while going over correspondence.

More recently, however, Bobo's inner circle has expanded to include several others, including County Administrator William E. Eakle, Administrative Manager Buddy Roogow and Eugene Weiss, a second administrative assistant.

The degree to which Bobo relies on these people has been unique to her administration, council members and county staff say, and is a function not only of the growing workload in a county becoming ever more complicated, but also of her leadership style. Bobo conceded that she is comfortable delegating both tasks and authority, and prefers a group approach to solving problems.

"It's just impossible to do everything yourself, and as trite as it sounds, if you try to, you're not going to do any of it well," she said.