News Summary: S&P 500 rises, boosted by Apple

APPLE-ICAHN: Apple rose sharply after billionaire investor Carl Icahn disclosed on Twitter that he had acquired a large but unspecified stake in the technology company. He also said that he had just had a "nice conversation" with Cook about his belief that the maker of the iPhone and iPad should be using even more of its $147 billion in cash to buy back its own stock.

PLANE TROUBLE: Airline stocks declined after the Justice Department and a number of state attorneys general challenged the proposed merger of US Airways and American Airlines' parent company, AMR Corp., saying it would force customers to pay higher fares and fees.

RISING YIELDS: Treasury yields rose sharply on signs that global growth may be picking up as more signs emerge that Europe is moving out of recession. That pushed down housing stocks but helped banks, which should generate better profit margins with higher borrowing costs.