The Prince George's County Council selected Gerard McDonough yesterday as its next chairman, capping a year of controversy by choosing the man who has been at the center of it all.

For McDonough, both admired and villified as the strong arm of the council and the keeper of the Winfield Kelly flame, the moment was finally his after seven years of council duty spent largely, though effectively, in the background.

"What it comes down to, ironically, is that I'm now providing the prescription that council member William Amonett did in 1978; I'm the noncontroversial candidate," said McDonough, a longtime friend and ally of former county executive Winfield Kelly and a council member whose entire political career has been tied to the Democratic slate Kelly once headed.

Along with newly elected Vice Chairwoman Deborah R. Marshall, McDonough assumes public leadership of the council not only in an election year, but in the wake of the most controversial session in recent memory.

Over the past 12 months the council narrowly defeated abortion restrictions in county hospitals, approved a redistricting plan, rejected a proposed county hospital lease, adopted far-reaching zoning changes and awarded the county's multimillion-dollar cable television franchises. Though McDonough's political skills were most evident in his well-publicized role in steering one cable award to a company represented by Kelly, he has played a key role in nearly every deliberation before the council, whether by vote trading, appointment selection or the orchestration of voting blocs.

Next year, however, McDonough hopes to put these skills to use under less dramatic circumstances. "I view my role primarily as conciliatory," he said yesterday. "Even though it's an election year, we as a council and a delegation have some problems," he added, referring to some difficult environmental and budget issues that must be addressed next year.

In his acceptance speech, McDonough said he will try to ensure that "intra- or interparty competition remains out in the campaigns where it belongs," and does not interfere with goverment services, especially in the face of anticipated federal cutbacks.

McDonough and Marshall were selected uanimously by the council after Parris Glendening decided he would not seek a third term as chairman. Glendening said he wants to devote more time to his campaign for county executive.

Three times in the last seven years, McDonough stepped aside to allow others to take the chairmanship or vice chairmanship that he coveted and might have won. Most recently, he agreed to support Glendening for an unprecedented second consecutive term as chairman in return for Glendening's backing of McDonough's friend, John Lally, in Lally's losing bid to replace Francis Francois on the council.