Apple Inc. has asked a California court to issue a preliminary injunction to block sales of Samsung Electronics Co.'s new Galaxy Nexus smartphone, alleging the device infringes four Apple patents.
The step marks another escalation of the sprawling legal battle between the world's two top sellers of smartphones, with Apple redrawing its arguments to account for Samsung's rising position in the business.
Apple argues the new Samsung phone -- which uses a new version of Google Inc.'s Android operating software dubbed Ice Cream Sandwich -- is the most credible competitor yet to its iPhone and poses a potent threat to Apple's market share.
Apple's suit, filed Wednesday in US District Court in San Jose, accuses Samsung of violating patents that are distinguishing features of the iPhone.
The suit contrasts with Apple's original case against Samsung, filed in the same court last April and expected to go to trial this summer, by concentrating on technical patents rather than design-oriented ones.
One patent, for example, covers a function known as slide-to-unlock, in which customers gain access to their phones by sliding an image of a button across the screen.
Another patent covers technology for searching multiple sources of information at once, an element of a voice-search technology called Siri introduced last year.
Siri uses the function when customers speak into their phones, and are given responses that gather information from the phone and several different websites.
Apple argued the Galaxy Nexus acts in the same way when customers type in their requests into the device's search function.
Apple also said Samsung violated a patent for detecting bits of information, such as a phone number in an email, that customers can tap on to quickly make a phone call.
In December, the International Trade Commission banned Android phones made by Taiwanese smartphone maker HTC Corp. that the agency said violated that patent.
Samsung said in a statement it was aware of the new filings by Apple and it would continue to "defend against Apple's claims to ensure our continued innovation and growth."
An Apple spokeswoman reiterated the company's earlier statements that Samsung copied its products.
Apple's latest efforts highlight the big stakes and tightening competition in smartphones. During the fourth quarter, Apple inched out Samsung, with 23.5 percent of global smartphone shipments compared to Samsung's 22.8 percent, according to market research firm IDC.
In the third quarter, Apple's share had dropped to just 14 percent, compared to Samsung's 23 percent, as consumers held off to buy a rumored new iPhone.