NEW YORK--A few blue-chip stocks posted modest gains yesterday as the battered market showed some signs of stabilizing amid continued heavy trading.

Most major U.S. exchanges, mean-while, closed two hours early to curb the enormous volume building up since Monday's historic collapse.

The Dow Jones average of 30 industrials, which plunged a record 508 points on Monday, was up 4.48 to 1,954.91 by noon on Wall Street. In the first half hour of trading the closely watched index had slid about 22 points and by 11 a.m. it was up 33 points.

On Thursday, the closely watched index skidded 77.42, its sixth worst daily loss following two days of record gains.

Losers outnumbered gainers by nearly 3 to 2 in the overall tally of New York Stock Exchange-listed issues today, with 978 down, 656 up and 299 unchanged.

Volume on the Big Board came to 157.80 million shares with two hours to go, off from the 212.43 million shares traded at the same point Thursday.

"We're seeing positive money flow today. It looks like a lot of the panicky institutional liquidation is over," said Edward P. Nicoski, a technical analyst for Piper Jaffray & Hopwood Inc.

Nicoski said some investors who had fled to the credit markets following Monday's collapse were now taking profits from bonds and putting that back into equities.

"Our retail clients are just buying. They think some of the blue chips are the best buys in many years," he said.

Still, many traders feel the market has a long way to go before its back on its feet.

"We're still trying to recover from the plunge we took on Monday," said Hildegarde Zagorski, a market analyst at Prudential-Bache Securities Inc. "The market is convelescing."

Traders said stock prices started off on a depressed note after overseas markets continued to post huge losses, capping the worst week in global equity trading since the Great Depression.

Domestic traders said they also were disappointed that President Reagan didn't offer a more forceful solution to the stock market crisis in his television press conference late Wednesday.

Many said they were concerned that Reagan and the Congress would fail to act decisively to correct the massive federal budget deficit, trade deficit and long-term U.S. debt that many believe are key causes of the market's anxiety.

Two peices of positive economic news released today were virtually ignored by Wall Street. The government reported that consumer prices rose a modest 0.2 percent in September while the gross national product surged ahead at a 3.8 percent clip.

The NYSE's composite index of all its listed common stocks fell 0.30 to 139.15. At the American Stock Exchange, the market value index was off 3.78 at 265.24.