Apple spokesman Steve Dowling dismissed the legal dispute. "We think Cisco's trademark lawsuit is silly," Dowling told Dow Jones.
Several other companies use the iPhone name for products, and "we are the first company to use the iPhone name for a cellphone" instead of a home phone using Internet technology, he said. Dowling declined to comment on why the negotiations broke down.
Apple shares slipped slightly in after-hours trading, falling 40 cents, or 0.4%, to $96.60. They ended the regular session up $4.43.