Amazon.com, the world’s biggest online retailer, was hit with more intellectual property lawsuits in the third quarter.

In its quarterly earnings report filed yesterday with the U.S. Securities & Exchange Commission, Amazon, No. 1 in the Internet Retailer Top 500 Guide, revealed that the company is now battling 18 separate intellectual property lawsuits, including eight filed in September. Among those is a case filed in Oregon District Court…Select Retrieval Inc. filed a lawsuit for infringement of a patent for data display software with actions and links that are integrated with various types of data.

Amazon is going to have to do some serious sales this holiday season to cover those legal fees. Ouch.

See Internet Retailer for more info and full list of lawsuits.