President Carter has decided to appoint Max N. Berry, a politically active Washington lawyer, as chairman of the powerful Pennsylvania Avenue Development Corporation, the White House announced yesterday.

The appointment of Berry, 44, who was chief fund-raiser for Mayor Marion Barry during his 1978 campaign, resolves a nagging political problem for both the White House and local officials and provides new leadership for an agency that has a commanding role in the development of downtown Washington.

The chairmanship of PADC, the independent agency overseeing hundreds of millions of dollars of construction on Pennsylvania Avenue, has been vacant since chairman Joseph B. Danzansky died last Nov. 8.

The agency is authorized to spend up to $200 million and to choose architects and builders for numerous hotel, commercial, residential and office properties to be constructed along Washington's historic main street. The properties under the agency's control are the last major parcels of land suitable for large-scale development in the old downtown area.

Berry's appointment was held up for several months, according to sources, while both the mayor and Berry wavered over whether to support Carter or Sen. Edward M. Kennedy in the presidential race.

Until last October, Berry was a member of a local dump-Carter group called the D. C. Committee for a Democratic Alternative. The mayor never went so far as to publicly renounce Carter, but he reportedly wavered on which candidate to support and only reluctantly went with Carter.

Both men announced their support of Carter last Jan. 21 in full-blown press conference attended by First Lady Rosalynn Carter.

But Berry's appointment was further stalled, sources said, by a local political rift. D. C. Democratic State Committee Chairman Robert B. Washington Jr., an active Carter supporter, supported another candidate for the post -- Thomas J. Owen, chairman of Perpetual Federal Savings and Loan Association, the city's largest savings and loan institution.

White House sources said bickering among local officials was responsible for the delay in the appointment, but would not elaborate.

In the meantime, Thomas F. Murphy, former president of the International Bricklayers Union, was named acting chairman of PADC. This move ended an almost total stoppage of the agency's activities, since PADC rules make it difficult for the agency's board of directors to make decisions on the disposition of property and the negotiation of leases without a chairman.

Local business leaders said yesterday that they felt the agency had been effectively stalled under the acting director, and welcomed Berry's appointment.

The business leaders expressed reservations about what they called Berry's lack of experience in the real estate field -- he specializes in international law -- but they said they believed he could handle the job.

"I'm delighted it's a local person," said John R. Tydings, executive vice president of the Greater Washington Board of Trade. "I'm very, very supportive of a local feel to that board. I think the board needs his [Berry's] skills at negotiation and diplomacy."

"I think he'll do a good job," said attorney R. Robert Linowes, a former Board of Trade president.

"He has minimal experience with real estate and development, but in my experience he's a bright person. Now we've got to move forward expeditiously and complete the job" of developing the avenue.

Berry, an Oklahoma native, is a graduate of the University of Oklahama and Georgetown University Law Center. He is senior partner of the Washington firm of Berry, Epstein, Sandstrom and Blatchford, and is active in local politics. Recently, he has been raising campaign funds for City Council member John L. Ray (D-At Large), who is running for re-election this fall.