NEW YORK (CNN/Money) - Record high crude oil prices weighed on stocks Monday morning, although a pair of upgrades for Dow stock AIG and some mega-merger news helped temper the impact.

The Dow Jones industrial average (down 99.46 to 10,404.30, Charts), the Nasdaq composite (Research) and the broader Standard & Poor's 500 (up 1.09 to 1,174.01, Charts) index all hovered 0.1 percent lower around 15 minutes into the session.

Stocks slumped Friday on rising oil prices and worries about inflationary signs in the economic news. Similar concerns weighed Monday in the early going.

Oil jumped to a new record trading high of $58.28 a barrel in electronic trading before pulling back some to $57.92. On Friday, light crude oil for May delivery closed at $57.27 a barrel, a new closing high.

In corporate news, shares of troubled insurer American International Group (unchanged at $50.95, Research) rose 1.5 percent after brokerages Smith Barney Citigroup and Morgan Stanley both upgraded it on valuation. The stock has been hit hard amid ongoing probes of its accounting by both the Securities and Exchange Commission and the New York Attorney General's office.

In other news, ChevronTexaco said it will buy Unocal in a cash and stock deal worth around $16.4 billion. Shares of ChevronTexaco (unchanged at $59.31, Research) lost around 1 percent, while Unocal (unchanged at $64.35, Research) fell around 5 percent on disappointment that the deal wasn't worth more.

Treasury prices fell, raising the yield on the 10-year note to 4.46 percent from 4.45 percent late Friday. Bond prices and yields move in opposite directions.

In currency trading, the dollar rose versus the euro and the yen.

COMEX gold fell $1 to trade at $427.30 an ounce.

In global trade, Asian-Pacific stocks ended mostly lower and European shares fell at midday.