(Updates with response from HTC and Motorola and comment from patent lawyer.) By Roger Cheng Of DOW JONES NEWSWIRES NEW YORK (Dow Jones)--NTP Inc., best known for getting a settlement from Research In Motion Ltd. (RIMM, RIM.T) over email technology, is shifting its legal sights to a number of smartphone makers, including Apple Inc. (AAPL) and Google Inc. (GOOG). NTP, which holds a number of patents but doesn't manufacture any products, filed a lawsuit Thursday in the U.S. District Court in the Eastern District of Virginia against Apple, Google, HTC Corp. (HTCXF, 2498.TW), LG Electronics Inc. (066570.SE), Microsoft Corp. (MSFT) and Motorola Inc. (MOT) over eight patents related to the wireless delivery of email to cellphones. Legal tactics increasingly have become common among technology players looking to defend their turf, intimidate competitors or extract an additional revenue stream through a forced licensing agreement. NTP has precedence--Research In Motion paid the company $612.5 million in a settlement to prevent a potential injunction of its popular Blackberry smartphones--which makes it a legitimate threat to other smartphone makers. "Use of NTP's intellectual property without a license is just plain unfair to NTP and its licensees," company co-founder Donald E. Stout said in a statement. "We took the necessary action to protect our intellectual property." NTP is a privately held company co-founded by inventor Thomas Campana to hold the patents on technology he developed throughout his career. NTP calls him "the inventor of wireless email." Campana, who died in 2004, held 50 patents. Apple and Microsoft declined to comment on the pending litigation. HTC and Motorola said they haven't seen the lawsuit. Spokesmen for the other sued companies weren't immediately available for comment. NTP has also launched patent-infringement suits against wireless providers such as AT&T Inc. (T), Deutsche Telekom AG's (DTEGY, DTE.XE) T-Mobile USA, Sprint Nextel Corp. (S), and Verizon Communications Inc. (VZ) and Vodafone Group PLC's (VOD, VOD.LN) Verizon Wireless. The litigation has been stayed pending a full review of the patents by the U.S. Patent and Trademark Office. NTP's aggressive legal tactics have led some critics to call the company a "patent troll." But Ron Epstein, a licensing lawyer hired by NTP to negotiate deals with the smartphone makers, said the intellectual property developed by Campana is legitimate and crucial to how wireless email is delivered today. The company is still open to further negotiations with the companies. "NTP is always open to talks to reasonable licensing terms," Epstein said. It's a logical move for NTP after settling with RIM and going through the re-examination process. "They've got an asset, and they're trying to get every dollar out of it that they can," said Mark Kesslen, a patent attorney for Lowenstein Sandler. Kesslen said the amount of the settlement will likely be less since the companies were well aware of the RIM suit and likely have some sort of technology "workaround" handy. Nokia Corp. (NOK, NOK1V.HE) and closely held email systems provider Good Technology Inc. have both signed licensing deals with NTP. The increasing amount of jockeying for position among smartphone manufacturers has created fertile ground for courtroom clashes. Last month, Apple filed a second complaint against HTC over software and technology for mobile devices after HTC launched a countersuit, embroiling the two deeper into their legal spat. RIM and Motorola recently settled a patent dispute, with RIM agreeing to a one-time payment and ongoing royalties to Motorola. At the same time, the pace of smartphone launches has accelerated. On the heels of the launch of the iPhone 4, a new Motorola Droid phone and a line of Galaxy S smartphones from Samsung Electronics Co. (SSNHY, 005930.SE) are expected in the coming weeks. -By Roger Cheng, Dow Jones Newswires; 212-416-2153; roger.cheng@dowjones.com (Nathan Becker contributed to this article.) (END) Dow Jones Newswires July 09, 2010 12:56 ET (16:56 GMT)