People test a Kindle 2 in New York in February 2009. US online retail giant Amazon has filed a lawsuit against Discovery Communications alleging it infringed four of Amazon's e-commerce patents, The Wall Street Journal reported on Tuesday.

US online retail giant Amazon has filed a lawsuit against Discovery Communications alleging it infringed four of Amazon's e-commerce patents, The Wall Street Journal reported on Tuesday.

The newspaper said the suit alleges infringement of patents covering search engine and recommendation technology by an e-commerce site run by Discovery, an operator of cable-television networks based in Silver Spring, Maryland.

It said the suit was filed last week in US District Court in Seattle.

Amazon's suit comes after Discovery filed a patent infringement lawsuit against the Seattle, Washington-based online retail company in March over its popular , the Kindle.

Discovery, in the suit filed in a US District Court in Delaware, claimed violated a patent it registered in November 2007, and said the Kindle infringes Discovery's .

Discovery said Kindle violates its development of a scheme -- the way Amazon protects the books it sells for the handheld product.

The Journal also reported that Amazon had filed counterclaims in connection with Discovery's suit.

(c) 2009 AFP