The stock market headed higher today, rebounding from last week's setback. The Dow Jones average of 30 industrials, down 34.95 points last week, rose 19.30 to 2,881.68 by noontime on Wall Street. Gainers outnumbered losers by about 9 to 8 in nationwide trading of New York Stock Exchange-listed issues, with 681 up, 611 down and 513 unchanged. Analysts said traders were doing some selective ``bargain-hunting'' in the blue chips while they awaited a broad array of economic reports due from the government this week. Among the monthly statistics on the agenda for Wall Street are the producer price index of finished goods, due on Thursday, and the consumer price index and the nation's trade balance, both on Friday. If all goes as expected, brokers say, the data will support the popular view that economic growth is plodding along at a pace slow enough to permit inflation and interest rates to ease. However, they add, any surprises in the numbers could unsettle some of the optimism that built up during the rally the carried stock prices to new highs as recently as last Monday. Boeing climbed 1&rsqb; to 56~ on expectations of a big order from Korean Airlines for Boeing 747-400 jets. Elsewhere among the blue chips, International Business Machines rose 1&lsqb; to 119~; American Telephone & Telegraph &rsqb; to 42&rsqb;; General Motors | to 49&lsqb;, and DuPont &rsqb; to 39{. Microcom Inc. tumbled 8{ to 9} as the most active issue in the over-the-counter market. Late Friday the company projected a loss for the fiscal quarter ending June 30, saying major domestic distributors were overstocked with its software and modem products. The NYSE's composite index of all its listed common stocks added .52 to 196.57. At the American Stock Exchange, the market value index slippesd .09 to 361.08. Volume on the Big Board came to 60.05 million shares at noontime, against 69.98 million at the same point Friday.