Stock prices sagged again today, extending Tuesday's sharp decline. The Dow Jones average of 30 industrials, down 78.22 points on Tuesday, was off 6.18 at 2,439.36 by 3 p.m. today on Wall Street. Losers outnumbered gainers by almost 5 to 2 in nationwide trading of New York Stock Exchange-listed issues, with 420 up, 1,028 down and 495 unchanged. Analysts said rumors of increasing tensions in the Persian Gulf caused some fresh problems for the market. The atmosphere was already gloomy, they noted, following Tuesday's upsurge in oil prices to above $40 a barrel. Today crude-oil futures for November delivery pushed past $41 a barrel in early trading on the New York Mercantile Exchange, then dropped back to the neighborhood of $39.50. Recession worries have intensified of late as analysts continue to cut their earnings estimates for a wide range of companies. Profit reports for the third quarter of the year will reach flood stage over the next couple of weeks. Motorola rose 1&lsqb; to 53~ in active trading after taking a 7-point drop Tuesday, when the company posted a quarterly earnings gain that fell short of expectations. Losers among the blue-chip industrials included Aluminum Co. of America, down 2{ at 57\; American Telephone & Telegraph, down &rsqb; at 31|; General Electric, down | at 52\, and Mobil, down ~ at 58|. The NYSE's composite index of all its listed common stocks dropped .91 to 166.50. At the American Stock Exchange, the market value index was down 2.66 at 300.39. Volume on the Big Board came to 133.34 million shares with an hour to go.