Wall Street closed mixed in a trading day marked by news of deals.

Warren Buffett's Berkshire Hathaway announced it would buy the Burlington Northern Santa Fe Railroad in a $34 billion transaction. Stanley Works said it has agreed to buy Black and Decker.

Technology stocks suffered after Morgan Stanley said inventories were beginning to grow in that sector and downgraded Intel.

By closing, the Dow had lost 18 points to 9772, while the Nasdaq added eight points to 2057. The S&P 500 gained three points to 1045, while crude prices tacked on $1.47 to trade at $79.60 a barrel.