Students walk out of a showroom at the headquarters of Samsung Electronics in Seoul
Students walk out of a showroom at the headquarters of Samsung Electronics in Seoul, South Korea, on Oct. 28. REUTERS

Apple Inc. failed to convince a U.S. judge to block Samsung Electronics from selling some Galaxy smartphones and tablets in the U.S. market, depriving the iPhone and iPad maker of crucial leverage in a global patent battle between the two companies.

In a ruling released late on Friday, U.S. District Judge Lucy Koh in San Jose, Calif., denied Apple's request for a preliminary injunction against Samsung.

The two companies are engaged in a bruising legal battle that includes more than 20 cases in 10 countries as the they jostle for the top spot in the smartphone and tablet markets.

Also on Friday, an Australian court extended a halt on sales of Samsung's latest Galaxy tablet in the country by at least a week, as Apple appeals a ruling that had ended the ban.

Apple sued Samsung in the United States in April, saying the South Korean company's Galaxy line of mobile phones and tablets slavishly copies the iPhone and iPad.

On Friday, however, Koh rejected Apple's bid to ban sales of three smartphone models, as well as the Samsung Tab 10.1.

It is not clear that an injunction on Samsung's accused devices would prevent Apple from being irreparably harmed, Koh wrote.

Apple representative Kristin Huguet on Friday referred to previous Apple statements about the case, saying that Samsung's blatant copying is wrong. Samsung representatives did not immediately respond to a request for comment.

Apple could still prevail in the overall lawsuit. But its inability to win a quick halt to Galaxy sales in the United States comes as the stakes skyrocket in one of the fastest-growing consumer-electronics markets.

Under Pressure

Global tablet sales are expected to explode to more than 50 million this year. Apple, which has sold more than 30 million iPads so far, is expected to continue to dominate the market in the short term.

Apple's new CEO Tim Cook is under pressure to show he can fill the large shoes of his predecessor, late Silicon Valley titan Steve Jobs. But in his first quarterly result unveiled as permanent CEO, Apple stunned Wall Street, missing expectations for the first time in years.

Analysts said customers held off buying iPhones in the September quarter, waiting for the October launch of the latest iPhone 4S.

But tablets proved a bright spot. The company moved 11.12 million units during the quarter despite attempts by various manufacturers, including Samsung, to capture a slice of the tablet market.

Now has also entered the fray with its Kindle Fire tablet, but Samsung's Galaxy lineup is widely deemed the closest rival in terms of capability and design to the iPad.

Acknowledging the competition, Cook said it was reasonable to say none of Apple's rivals have gained any traction, and he expected the tablet market to be bigger than personal-computer market in the long term.

In her ruling, Koh wrote that for some of the smartphones, Apple has established a likelihood of success on the merits at trial.

Koh added that Apple would likely prove Samsung infringed one of its tablet patents. However, Apple had not shown that it was likely to overcome Samsung's challenges to the patent's validity, Koh wrote.

Apple must demonstrate both infringement and validity to succeed in its lawsuit.

The case in U.S. District Court, Northern District of California is Apple Inc v. Samsung Electronics Co Ltd et al, 11-1846.

(Reporting by Dan Levine; Editing by Yoko Nishikawa)