Rep. Geraldine A. Ferraro (D-N.Y.) was chosen yesterday as Walter F. Mondale's running mate, sources said early this morning, and Mondale will announce the choice of his vice presidential candidate at the Minnesota state capitol in St. Paul at 1 p.m. EDT.

Ferraro, who would be the first woman selected to run for the vice presidency, was booked on a flight scheduled to leave San Francisco, site of next week's Democratic National Convention, for Minneapolis at 3:40 a.m. EDT.

Ferraro, 48, is in her third term in Congress representing New York's 9th Congressional District in Queens and had served as an assistant district attorney there.

A member of the House Budget Committee, she was chairman of the platform committee for this year's convention.

Ferraro appeared publicly in San Francisco shortly after Mondale reportedly talked to her by telephone and, acting in an unusually upbeat manner, said she was "still in the running for the job."

Her husband, real estate developer John Zaccaro, was booked on a flight from New York to Minneapolis this morning.

Mondale, the likely Democratic presidential nominee, and Ferraro are to meet the press today in St. Paul and fly together Friday to Elmore, Minn., Mondale's boyhood home town, for a public rally and news conference.

Mondale's decision came during a day of meetings with top aides, including campaign chairman James A. Johnson and Washington attorney John Reilly, who headed the search process.

Johnson said Mondale made his choice about 7 p.m. EDT and called that person shortly thereafter. He said the offer was accepted immediately.

Sen. Gary Hart (D-Colo.) and San Francisco Mayor Dianne Feinstein told people last night that they had not been picked.

The whereabouts of Los Angeles Mayor Tom Bradley could not be determined early today, fueling speculation that he still may be in the running. But there was no indication that the 66-year-old mayor was the choice.

Massachusetts Gov. Michael S. Dukakis talked with Mondale on the telephone last night, but the the call, confirmed by Dukakis' press secretary, appeared to have occurred several hours after Mondale made his decision.

San Antonio Mayor Henry Cisneros said last night that he talked with Mondale, but Texas sources indicated that the 37-year-old mayor is not Mondale's choice.

Reilly confirmed then that Mondale had not spoken to Hart, the first clear indication that the likely Democratic presidential nominee had not turned to his chief rival for the nomination to the second spot on the national ticket.

Ferraro, the personal choice of House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.), addressed the World Affairs Council in San Francisco late yesterday.

She told reporters just before her speech that she was "still in the running." That statement apparently was made after Mondale had made his choice. After addressing the council, she answered questions. One person asked if there should be so much concern about whether a woman was in the running for the vice presidency. "Who's kidding who?" Ferraro responded.

She recalled her graduation from law school in 1960 and subsequent application for a job at a "prestigious Wall Street law firm." She said she was brought in for five interviews.

"They drag you back and forth, kind of like I'm doing now," she said.

At the fifth interview, she said, she was told that she was "terrific, but we're not hiring any women this year." When people ask her if she feels bad about being considered for the vice presidency because she is a woman, she said, "I don't feel the least bit badly about it."

Clearly in an ebullient mood, she said, "I'm delighted there's no longer that big sign outside that door of the office of vice president that says white males only need apply. It's our turn, folks!"

Washington Post staff writer Eleanor Randolph reported early this morning that security around Ferraro's hotel in San Francisco appeared to have been beefed up and that reporters and television cameras were camped in the hotel.

One piece of conflicting evidence last night was a report that New York Gov. Mario M. Cuomo had not been informed of Mondale's decision. Cuomo, first choice of several Mondale aides as a vice presidential candidate, had publicly urged that Ferraro be the choice after meeting with Mondale in Boston last Thursday.

Cuomo, who had taken himself out of the running for the No. 2 spot, will give the keynote address Monday night at the Democratic National Convention in San Francisco.

Ferraro's prospects suddenly brightened late Tuesday when it was reported that Reilly had flown to San Francisco to see her. On the same day, Berman was in New York talking to her husband.

Earlier in the week, Ferraro had told friends that she was angry at reports that Mondale, through aides, was signaling disappointment in her performance in a meeting at Mondale's home in North Oaks, Minn., on July 2.

Sources said she had told friends that she felt she was being treated shabbily and that being publicly considered for the national ticket and then dropped could hurt her prospects for a possible Senate race in 1986. Those feelings were quickly relayed to the Mondale campaign, sources added.

Mondale called Ferraro Sunday to tell her that he was not disappointed in the way she had handled her interview with him, and the Reilly visit appeared to be more than an effort to soothe ruffled feathers.

Bradley was the first person interviewed by Mondale at the former vice president's suburban home in North Oaks after the Democratic primary season ended June 5. Mondale later referred to the mayor, an old friend, as "a man of God," but there were indications that Mondale was concerned about Bradley's age, 66.

Dukakis, who stood by Mondale during the worst weeks of the long primary fight last spring and was praised by Mondale as one of his best friends in politics, has been considered a possible choice, if Mondale decided he did not want to risk picking a woman or a minority running mate.

There were fewer signs earlier yesterday that the Mondale campaign was seeking background information on Bradley or Dukakis.

Feinstein told two persons in San Francisco last night that she had no travel plans. Thomas Eastham, her press secretary, told Washington Post staff writer Jay Mathews that he talked to the mayor at dinner last night and that she said she had not been chosen.

"My intention is to support the ticket," she said, according to Eastham. "I look forward to greeting Mr. Mondale in San Francisco."

The briefing by Johnson and Reilly in Minnesota followed a day of rumors and conflicting signals. Mondale has been secluded at his home for several days, meeting with top aides, and the entire Mondale campaign put a tight lid on events involving the choice of a running mate.

Others besides Cuomo who had pulled out publicly included Sens. Dale Bumpers (D-Ark.) and Sam Nunn (D-Ga.).

Sen. Lloyd Bentsen (D-Tex.), the only white male who traveled to Minnesota to meet with Mondale, concluded earlier this week that he would not be the choice. He decided to await a decision, rather than withdraw publicly, fearing any public statement might look as if he were turning his back on Mondale, a longtime friend.