NEW YORK (CNNMoney.com) - Stocks stumbled Friday as concerns about the economy, inflation and interest rates unnerved investors despite a blockbuster deal in the energy sector.

The Dow Jones Industrial average (down 30.02 to 10,989.09, Charts) fell 0.3 percent, while the broader Standard & Poor's 500 index (down 1.10 to 1,244.50, Charts) dipped 0.1 percent. The tech-heavy Nasdaq composite (down 1.51 to 2,121.47, Charts) edged lower.

All three major gauges zigzagged between gains and losses throughout the session after the government reported that durable goods orders fell in May, versus forecasts for a small rise. The news heightened investors' nervousness before the Federal Reserve's policy meeting next week.

The Dow ended the week down 0.2 percent, while the Nasdaq fell 0.4 percent and the S&P lost 0.5 percent.

"Investors are scared to buy and scared to sell - we're trapped in day-to-day volatility," said Tony Dwyer, equity market strategist at FTN Midwest Research.

And with a slew of economic and earnings reports before the Fed's meeting June 28-29, next week promises to be more of the same.

"Hold tight," Dwyer advised.

Of the 30 stocks in the Dow, 20 fell and 10 rose.

In merger news, shares of Anadarko Petroleum (down $3.49 to $44.90, Charts) sank more than 7 percent after the oil and gas producer said it is buying two rival energy companies, Kerr-McGee (up $18.31 to $68.61, Charts) and Western Gas Resources (up $18.76 to $59.67, Charts) for about $21 billion. Kerr-McGee surged 36 percent, while Western Gas was 46 percent higher.

In a smaller deal, Energy Partners (up $1.15 to $19.17, Charts) said it will buy Stone Energy (up $0.48 to $46.71, Charts) for $1.4 billion, sending shares of both companies higher.

On the earnings front, shares of Oracle (up $0.57 to $14.90, Charts) rose 4 percent after the software maker posted a higher quarterly profit after the closing bell Thursday in line with its updated forecast.

Shares of Synnex (up $1.47 to $19.29, Charts) soared more than 8 percent Friday after the computer hardware distributor reported a lower quarterly profit that beat analysts' expectations.

Contract electronics manufacturer Solectron (up $0.14 to $3.44, Charts) posted a profit for its fiscal third-quarter, reversing a year-earlier loss and sending shares up over 4 percent.

Elsewhere, Six Flags (down $1.90 to $5.55, Charts) sank 25.5 percent after the theme-park operator said reaching its prior outlook for adjusted earnings before interest, taxes, depreciation and amortization would be "extremely difficult," and Standard & Poor's downgraded its outlook to "negative" from "stable."

The Wall Street Journal reported that about 37,000 hourly workers have accepted buyout offers from General Motors (down $0.30 to $26.97, Charts) or bankrupt auto parts maker Delphi (Charts), helping those two troubled companies shave labor costs. Shares of the automaker fell over 1 percent, making it one of the Dow's biggest losers.

Alcoa (up $0.19 to $30.18, Charts) was the Dow's biggest gainer on news that the aluminum producer was in talks to establish operations in other African countries besides Guinea and Ghana. Rival Alcan (up $0.50 to $43.79, Charts) was also higher after signing memorandum with Ghana to create a joint venture to explore development of a bauxite mine and alumina refinery.

In commodities markets, oil prices added three cents to $70.87 a barrel on the New York Mercantile Exchange.

COMEX gold rose $2.60 to $588.

Treasury prices rallied briefly on the weak durable goods number but then turned lower, raising the yield on the 10-year note to 5.22 percent from 5.20 percent late Thursday. The dollar edged higher against the yen and the euro.

Market breadth was negative and volume was light. On the New York Stock Exchange, decliners edged out advancers on volume of 1.4 billion shares. On the Nasdaq, losers narrowly beat winners as 1.6 billion shares changed hands.

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