Stock prices lost ground Friday in a session marked by more stormy activity in the battered bank issues.

Trading volume picked up sharply as Wall Street worked its way through a quarterly "triple witching hour."The Dow Jones average of 30 industrials dropped 5.94 to 2,512.38, extending its loss for the week to 51.73 points.

Declining issues outnumbered advances by more than 3 to 2 in nationwide trading of New York Stock Exchange-listed stocks, with 595 up, 928 down and 471 unchanged.

Volume on the floor of the Big Board came to 201.05 million shares, up from 145.10 million in the previous session. Nationwide, consolidated volume in NYSE-listed issues, including trades in those stocks on regional exchanges and in the over-the-counter market, totaled 232.82 million shares.

Friday marked the last trading in a series of options and futures on stock indexes, contracts which are used by professionals engaged in multiple computer-program strategies that also involve individual stocks.

Analysts said the turbulence generated by the witching hour made it difficult to draw many conclusions from the market's fluctuations.

But most observers agreed that little had happened to dispel the fears of recession and inflation that have been depressing stock prices since early summer.

The market hit its lows for the session at midafternoon when Chase Manhattan Corp. announced plans to reduce its dividend and take big charges for restructuring and possible losses on loans.

Many stocks soon bounced back from the selloff, but bank issues remained under pressure. Chase stock dropped 1 to 123/4, trading at its lowest levels, adjusted for splits, since the mid-1970s.

Manufacturers Hanover fell 27/8 to 23; Citicorp 7/8 to 153/4; Chemical Banking 3/4 to 17, and BankAmerica 1/2 to 201/4.

Scott Paper tumbled 67/8 to 343/8 after the company said its earnings for the third quarter and all of 1990 might fall short of its operating profits for the corresponding periods last year.

Among actively traded blue chips, General Motors dropped 1/4 to 365/8; International Business Machines 11/8 to 1063/4; Philip Morris 1/4 to 443/4, and Boeing 5/8 to 431/4.

On the plus side, General Electric rose 3/4 to 557/8 and American Telephone & Telegraph gained 7/8 to 313/8.

Milton Roy, which reached agreement to accept a merger bid from Sundstrand, jumped 33/4 to 263/4.

As measured by Wilshire Associates' index of more than 5,000 actively traded stocks, the market lost $4.85 billion, or 1.16 percent, in value.

The NYSE's composite index of all its listed common stocks dropped .19 to 171.03.

Standard & Poor's industrial index fell .52 to 367.10, and S&P's 500-stock composite index was down .16 at 311.32.

The NASDAQ composite index for the over-the-counter market slipped -2.18 to 362.25. At the American Stock Exchange, the market value index closed at 316.01, down 1.17.