Bargain-hunters, picking over a stock market that had taken heavy losses in the previous two sessions, went on a buying spree in the final hour of trading today that allowed the market to wipe out most of its early losses and finish mixed.

"There didn't seem to be any hard news on it," said Eldon A. Gromm, an analyst at Birr, Wilson & Co. "There just seemed to be some bargain hunting."

The Dow Jones average of 30 industrials, which had fallen a total of more than 24 points Friday and Monday and was down more than six points during Tuesday's trading, wound up with an increase of 1.47 to 834.89.

Declines outnumbered advances by a 9-5 spread on the New York Stock Exchange, but the NYSE composite common-stock index rose .04 to 55.79.

NYSE volume was 32.72 million shares, up from 30.48 million Monday.

Nationwide turnover in NYSE-listed issues, including trades in those stocks on regional exchanges and in the over-the-counter market, came to 37.44 million shares.

Among the gambling issues, Caesars World fell 2 3/4 to 66 7/8, Bally was off 3/4 to 72 1/2 and Holiday Inns dipped 3/8 to 17 3/8. On the American Stock Exchange, Resorts International class A stock dropped 7/8 to 41 3/4 as the most active issue and Golden Nugget fell 5/8 to 18 5/8.

Another gambling issue suffering a loss was Ramada Inns, which fell 1 7/8 to 10 3/8 and was the NYSE's most active issue.

The Standard & Poor's index of 400 industrial issues rose .19 to 110.81 while the S&P 500-stock composite was up .15 to 99.17. CAPTION: Picture, William T. Seawell, left, Pan Am chairman, talks with shareholders yesterday after the firm's annual meeting. AP