U.S. energy stocks rose on Monday as crude prices extended a string of record highs, nearing $64 a barrel, on concerns over oil supply. As the energy sector surged, the three major U.S. stock indexes trimmed gains to trade little changed, Reuters reported. The Dow Jones industrial average was up 8.04 points, or 0.08 percent at 10,566.91. The Standard & Poor's 500 index was up 1.25 points, or 0.12 percent, at 1,227.96 and the technology-laced Nasdaq Composite Index was down 4.68 points, or 0.21 percent, at 2,173.45. Exxon Mobil Corp., the world's largest publicly traded company, and rival energy companies Chevron Corp. and ConocoPhillips were among the top gainers in the S&P 500 index. Exxon shares, the top S&P mover, gained 2.15 percent to $59.36, followed by a 2.7 percent rise in Chevron to $61.95. Shares of ConocoPhillips rose 2.3 percent to $65.20. Shares in discount broker E*Trade Financial Corp. surged 10.3 percent to $16.39 after the company agreed to buy the online brokerage Harrisdirect from BMO Financial Group for $700 million. In other acquisition news, Whirlpool Corp., the U.S. largest appliance maker, sweetened its offer for Maytag Corp. to $1.6 billion, or $20 per share. Whirlpool rose 3.3 percent to $82.45 and Maytag soared 10 percent to $18.68.