The S&P 500, considered by market professionals the best indicator of stock performance, surpassed the mark shortly after noon following news of a fresh spate of takeover deals. The broad market index has lagged the Dow Jones industrial average in recovering from Wall Street's prolonged slump earlier this decade.

The S&P 500 rose as high as 1,529.87, then edged back to 1,525.10, up 2.35, or 0.15 percent, as cautious investors locked in some profits after weeks of gains. The index's advance was driven by buying in nontechnology sectors such as energy, materials, industrials and financials, S&P data showed. It is still well below its all-time trading high of 1,552.87 set on March 24, 2000, the same day the index reached its record close.

Reassuring Wall Street Monday that acquisition activity will keep up its record pace this year, General Electric Co. said it is selling its plastics division to Saudi Arabia's largest industrial company, Saudi Basic Industries Corp., for $11.6 billion.

The announcement followed news Sunday that telecommunications company Alltel Corp. agreed to be bought for $24.8 billion, and that China's upstart state investment company was investing $3 billion in Blackstone Group LP. Blackstone, the second-largest U.S. private equity firm, is planning an initial public offering for later this year, and has been on a buying tear; just last week, it snapped up credit card services provider Alliance Data Systems Corp. for $6.43 billion.

UP-AND-DOWN DAY FOR DOW

The Dow retreated modestly after venturing further into record territory earlier in the day. The blue chip index fell 13.65, or 0.10 percent, to 13,542.88 after hitting an intraday high of 13,586.03.

The Nasdaq composite index rose 20.34, or 0.80 percent, to 2,578.79, after reaching a six-year high of 2,587.87. The index rose as Amazon.com's stock saw big gains, and as investors bought up small-cap stocks, which have been trailing large-cap stocks this year.

The Russell 2000 index of smaller companies rose 9.99, or 1.21 percent, to 833.65, after hitting an intraday high of 837.19. It is still below its record close of 834.77 reached May 9.

In early 2000, all the major stock market indicators reached record highs, only to be dragged down by the end of the dot-com boom, recession, the 2001 terror attacks and a series of corporate scandals including the collapse of Enron Corp. The S&P 500 fell to a low of 776.76 in October 2002 at the depths of a three-year bear market on Wall Street.

The market recovered slowly, but it wasn't until last October that the more widely recognized Dow Jones industrial average surpassed its own previous closing high of 11,722.98. The Dow has gone on to barrel past 13,000 as Wall Street rallies on a mixture of corporate takeover news, respectable earnings and hopes for an interest rate cut.

After 24 record closes for the Dow this year, the S&P has finally caught up.

"This is new territory, but more importantly it serves as a reminder that the three broad indices are doing well. That should be the focus," said Arthur Hogan, chief market analyst at Jefferies & Co.

The Nasdaq, however, is unlikely to reclaim its record close of 5,048.62 anytime soon. The technology-dominated index was overinflated by investors eager to grab any high-tech stock.

MARKET DRIVEN BY ACQUISITIONS

The market is being driven in part by acquisitions, which have convinced investors there is an abundance of cash in the marketplace. The run-up in takeovers has been shepherded by a push from private equity firms; buyout shops have racked up more than $370 billion in global buyouts this year, and are on pace to beat last year's record of $730 billion, according to financial data provider Dealogic.

Although there has been strength in takeover activity, as well as signs of economic recovery in recent snapshots of U.S. manufacturing, many market watchers are nervous that the market has been driven by momentum trading rather than individuals putting money in stock-based mutual funds.

"People are buying the market because it's going up," said Brian Gendreau, investment strategist for ING Investment Management. "We'd like to see a stronger foundation for this market."

Bonds rose Monday. The yield on the benchmark 10-year Treasury note slipped to 4.79 percent from 4.81 percent late Friday. The dollar gained against other major currencies, and gold prices also rose.

Crude oil soared $1.33 to $66.27 a barrel on the New York Mercantile Exchange.

After two private equity firms said they were buying Alltel, the wireless company rose $4.39, or 6.7 percent, to $69.60.

General Electric rose 14 cents to $37.10 after agreeing to sell its plastics business.

In a day that was sluggish for many technology stocks, the standout was Amazon, the biggest gainer on the S&P 500 and the Nasdaq. A Citigroup analyst raised his price target after the Internet retailer said it would offer online music without copy protection technology. Amazon, which hit a seven-year high, closed at $68.30, up $5, or 7.9 percent.

Advancing issues outnumbered decliners by about 3 to 2 on the New York Stock Exchange. Consolidated volume came to 3.48 billion shares, up from 2.92 billion Friday.

The S&P's milestone comes during a light week for economic data. The few notable reports are Thursday's durable goods and new homes sales reports from the Commerce Department, and Friday's existing home sales data from the National Association of Realtors.