Zillow Inc.'s initial public offering registration showed five patent infringement claims against the Seattle company since 2009.
Two of the lawsuits against the real estate listing and mortgage rate search website company have been resolved. One was brought by the mortgage search website Mortgage Grader in October 2009 and the other by Source Search Technologies in May 2010.
Both resulted in out-of-court settlements requiring Zillow to pay patent licensing fees to each company.
Zillow's legal expenses increased by $400,000 in 2010 compared with 2009 because of the heightened litigation activity. The company did not disclose the portion of its $6.7 million general and administrative expense that went to cover legal costs in 2010.
Zillow said it contests the claims in the three other pending lawsuits.
CoreLogic, then a subsidiary of First American Corp. of Santa Ana, Calif., filed a suit against Zillow and numerous other providers of automated valuation model technology, claiming the technology companies' products infringe on CoreLogic's patent.
In a March 2010 suit that claims Zillow infringed on patents held by the location-based real estate search provider Smarter Agent, Zillow petitioned the Patent and Trademark Office to reexamine the three Smarter Agent patents.
That case is on hold pending the review.
The latest case, filed in September 2010, alleges that Zillow infringed on the patents of the online lead generator LendingTree, a unit of Tree.com Inc. of Charlotte, N.C.
In its IPO registration, filed April 18 with the Securities and Exchange Commission, Zillow said that it is seeking court declarations that the company is not infringing on LendingTree's patents and that the patents are unenforceable and invalid.
"Although we cannot be certain of the outcome of any litigation and claims, nor the amount of damages and exposure that we could incur, we currently believe that the final disposition of such matters will not have a material adverse effect on our business, financial position, results of operations or cash flow," Zillow said in its registration papers.
Zillow hopes to raise $51.75 million from the IPO.
