Apple has filed a lawsuit against HTC claiming infringement of 20 patents relating to the iPhone's user interface, hardware and architecture.
The lawsuit was filed in the US, as opposed to China where HTC is based.
"We can sit by and watch competitors steal our patented inventions, or we can do something about it," said Apple chief executive Steve Jobs.
"We've decided to do something about it. We think competition is healthy, but competitors should create their own original technology, not steal ours."
Apple made similar allegations against Nokia in December. Bruce Sewell, Apple's general counsel and senior vice president, said at the time that other companies "must compete with us by inventing their own technologies, not just by stealing ours".
HTC declined to comment directly on the patent claims, but did issue a statement. "HTC is a mobile technology innovator and patent holder that has been very focused over the past 13 years on creating many of the most innovative smartphones," the firm said.
"HTC values patent rights and their enforcement, but is also committed to defending its own technology innovations. HTC only learned of Apple's actions this morning via media reports, and therefore we have not yet had the opportunity to investigate the filings.
The firm added that until it has conducted this investigation, it is unable to offer comment on the validity of the claims being made against it.
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