NEW YORK — The stock market showed no clear trend on Thursday in its fourth consecutive mixed session as Wall Street cautiously approached another "triple witching hour."
However, pressured by investor fears of inflation and Treasury Secretary James A. Baker III's comments that the dollar's value might decline further, bond prices fell sharply.
Takeover news and speculation produced wide swings in several individual issues, while the rest of the stock market generally marked time.
The Dow Jones average of 30 industrials rose 4.78 to 1,774.18.
Volume on the New York Stock Exchange slowed to 132.24 million shares from 141.04 million on Wednesday.
Analysts said traders were likely to proceed cautiously until Friday's close, which marks the last trading in a set of stock index futures, stock index options and options on individual stocks.
On many similar occasions in the past, the stock market has experienced wide swings as professional traders complete computer program strategies involving the expiring options and futures and individual stocks.
This time around, experimental rules have been adopted calling for advance disclosure of last-minute buy and sell orders in some big-name stocks, in an effort to decrease the markets' potential volatility.
Overnite Transportation jumped 11 1/2 to 42 1/2. Union Pacific Corp. said it agreed to acquire the company for $43.25 a share in cash.
Western Pacific Industries, which agreed to be acquired by a private investor group for $155 a share, climbed 24 to 158 1/2.
USX rose 1 1/8 to 22 7/8. Financier Carl C. Icahn was reported to be accumulating the stock, close on the heels of plans by Robert Holmes a Court, the Australian investor, to buy as much as a 15% stake in the company.
BankAmerica led the active list, down 7/8 at 10 1/2. The company denied rumors that it was meeting with Federal Reserve officials to deal with its financial problems.
Lucky Stores, which has been the subject of takeover speculation, rose 1/8 to 30 5/8 with nearly 2 million shares changing hands.
In the bond market, the Treasury's key 30-year bond fell nearly $10 for each $1,000 in face value, and its yield jumped to 7.73% from 7.63% late Wednesday. Some shorter-term issues dropped as much as $20 per $1,000 in face amount.
In corporate trading, industrials and utilities fell 1 point in moderate to light dealings, Salomon Bros. said. Among tax-exempt municipal bonds, general obligations and revenue bonds both fell 1/2 point.