Stocks ended the session with modest gains Thursday after news of corporate acquisitions offset the impact of another record high for oil prices.

The Dow Jones Industrial Average rose 15.76, or 0.2 percent, to 10,450.63. The Standard & Poor’s 500 Index gained 2.78, or 0.2 percent, to 1,212.37. The Nasdaq Composite Index climbed 5.46, or 0.3 percent, to 2,134.37.

Johnson & Johnson said it won conditional approval from European competition authorities of its planned acquisition of heart device maker Guidant Corp. Johnson & Johnson said it expects a decision in October from the U.S. Federal Trade Commission on the deal. And automotive supplier Johnson Controls Inc. said it will pay $2.4 billion in cash for York International Corp., a maker of heating and cooling systems.

Crude futures reached $68 per barrel and settled at a record high for a second straight session, feeding Wall Street’s anxieties about a slowdown in consumer spending and economic growth. A barrel of light crude settled at $67.49, up 17 cents, on the New York Mercantile Exchange.

Among local companies, shares of Mercury General Corp. gained 4.9 percent to $58.40 after Standard & Poor’s said the L.A.-based personal automobile and homeowners insurance company would replace Hibernia Corp. in the S & P; MidCap 400 on Aug. 31. Capital One Financial Corp. is acquiring Hibernia.

Magnetek Inc. rose 2.8 percent to $2.90 after the L.A.-based company posted fourth-quarter earnings that were better than expected, beating analysts’ estimates. Magnetek forecast fiscal 2006 sales growth of 5 percent to 7 percent.

And Maguire Properties Inc. edged up 1.8 percent to $28.51 after it was reported that the L.A.-based real estate company has two Australian real estate investment trusts bidding heavily on a $1.1 billion portfolio it is selling. Macquarie Office Trust and DB Rreef Trust are competing to form a joint venture with Maguire to own the portfolio, according to a report today in The Australian newspaper.

On the down side, shares of Diodes Inc. lost 3.8 percent to $35.60 after the Westlake Village-based semiconductor maker registered to sell 2.5 million common shares, 1.75 million of which will be offered by the company. The remaining 750,000 shares will be sold by Diodes’ largest shareholder, Lite-On Semiconductor Corp.