Federal antitrust regulators may be able to build a case against Apple over its iTunes business because the company has a dominant share of the U.S. music download market, an antitrust lawyer told "Computerworld" (http://www.computerworld.com/s/article/9177460/Apple_vulnerable_in_iTune...). The size of Apple's share matters to the government, according to Hillard Sterling, an antitrust attorney at Chicago-based law firm Freeborn & Peters LLP.

The Justice Department is reportedly examining Apple’s tactics in the digital music market for digital music, and its staff members have talked to major music labels and Internet music companies. Apple is the largest seller of online music in the U.S., with 69% of the market, according to data from the NPD Group, research firm. Amazon’s MP3 store was in second place, with an 8% share. Apple is also the largest seller of music, with 26.7 percent of the overall market, up from 12 % in 2007.

"This has much stronger promise than the mobile device case because Apple's market share in digital music is much more attractive to government regulators," Sterling told "Computerworld." "The DOJ seems to be sniffing around for a stronger foundation for an antitrust case. And 70% is sufficient market share to raise the specter of a monopoly. It's a strong indicator to the government."

However, there's noting unlawful about having a monopoly, he added. What may be illegal is how a monopolist uses or abuses that position of strength.

"The next, more difficult step for the government would be to show an abuse of that power," Sterling told "Computerworld." "[The DOJ] has to show that a monopolist's conduct is truly anti-competitive. The big question is whether consumers are facing fewer choices or higher prices because of Apple's behavior."