Oil prices that surged past $65 a barrel before easing sent stocks sliding Wednesday, shaking investors’ optimism about the economy.

The Dow Jones Industrial Average fell 21.26, or 0.2 percent, to 10,594.41. The Standard & Poor’s 500 Index fell 2.25, or 0.2 percent, to 1,229.13. The Nasdaq Composite Index dropped 16.38, or 0.8 percent, to 2,157.81.

Climbing oil prices dulled advancing stocks, which rose earlier in the session on better-than-expected earnings from American International Group Inc. and a pledge on Tuesday by the Federal Reserve to keep further interest-rate increases at a measured pace. Crude futures hit an intraday record of $65 a barrel, the highest level since the New York Mercantile Exchange contract began trading in 1983, before easing to a record close of $64.90, up $1.83 for the day.

Among local movers, shares of IMPCO Technologies Inc. gained 6.7 percent to $4.79 after the Cerritos-based manufacturer of alternative fuel products and systems’ stock rating was raised to “buy” from “market perform” by analyst John Quealy at Adams Harkness. Late Tuesday, the company reported net income of $1.2 million (4 cents per diluted share) for the second quarter ended June 30, beating the average analyst earnings estimate.

And Unocal Corp. rose 0.8 percent to $66.10 after it announced that its shareholders approved the El Segundo-based oil company’s sale to Chevron Corp. for more than $17 billion, clearing the way to create the fourth-largest publicly traded oil company. Unocal said that shares representing 77.2 percent of the company’s outstanding stock, or 210.3 million shares, voted to approve the merger.

On the down side, shares of Center Financial Corp. fell 2.3 percent to $22.27 after the L.A.-based holding company of Center Bank said it filed for a five-day extension on filing its 10-Q quarterly financial report for the second quarter. The company said it needs additional time for its new auditor to review the work of the previous auditor and to complete an internal review of the accounting for certain interest rate swaps.

And Semtech Corp. slipped 2 percent to $17.51 after the Camarillo-based mixed-signal semiconductors manufacturer’s stock rating was downgraded to “average” from “buy” by analyst Nicholas Aberle at Caris & Co.