Shares of Apple (Nasdaq: AAPL), the world's most valuable technology company, fell 3 percent after Microsoft (Nasdaq: MSFT), the world's biggest software company, and Barnes & Noble (NYSE: BKS) announced a new partnership to battle the iPad.

By the close, Apple shares had lost $19.02 to close at $583.98, their lowest close since April 24. Their record high close in April was $644, bringing the shares once again close to a 10 percent correction.

As well, there was little reaction to a report published by New York Times Co.'s (NYSE: NYT) New York Times that the Cupertino, Calif.-based company had dodged taxes by deploying a strategy that while legal, raised questions of civic mindedness.

Apple didn't issue a formal announcement but told the Times it had complied with all U.S. laws. The company's auditor is Ernst & Young and its directors include Al Gore, U.S. Vice President from 1993 to 2001.

The tax story is the latest in a series of problems handed to CEO Timothy Cook, probably the highest-paid U.S. CEO last year, awarded with a million restricted stock units tied to Apple shares, valued around $584 million on Monday. First, the company hired the Fair Labor Association to deal with charges about bad labor conditions in China at plans operated by Foxconn (HK: 2308). Then it was sued by the U.S. Department of Justice for alleged antitrust violations in ebook prices.

Meanwhile, shares of Barnes & Noble nearly doubled, to $26.15, in pre-market activity and then rose about 52 percent, to close at $20.75, while those of Microsoft rose 3 cents to $32.01.