Apple Inc. was sued Wednesday over allegations its iTunes online music store and iPod music players are illegally using a patented method for distributing digital media over the Internet.

Atlanta-based ZapMedia Services Inc. sued Apple in U.S. District Court for the Eastern District of Texas, accusing the Cupertino-based company of violating two ZapMedia patents.

ZapMedia wants royalties on Apple’s sales of iPods and iTunes music, which reached $11 billion last year. The success of iTunes has helped make Apple the No. 2 music retailer in the U.S. behind Wal-Mart Stores Inc., according to market researcher NPD Group.

The patents in question cover a way of sending music and other digital content from servers to multiple media players, a broad description that could also apply to a wide swath of other companies selling digital media and the devices to play it.

ZapMedia applied for the patents in 1999. One was granted in March 2006, the other on Tuesday.

ZapMedia said it met with Apple to discuss licensing, but Apple rebuffed the offer.

“When someone takes our vision and our intellectual property without a license after several attempts, we have no option but to protect it through every means available to us,” Robert Frohwein, ZapMedia’s general counsel, said in a statement.

An Apple spokeswoman said the company doesn’t comment on pending lawsuits.