(Reuters) - The U.S. judge who tossed out one of the biggest court cases in Apple Inc's smartphone technology battle is questioning whether patents should cover software or most other industries at all.

Richard Posner, a prolific jurist who sits on the 7th U.S. Circuit Court of Appeals in Chicago, told Reuters this week that the technology industry's high profits and volatility made patent litigation attractive for companies looking to wound competitors.

"It's a constant struggle for survival," he said in his courthouse chambers, which have a sparkling view of Monroe Harbor on Lake Michigan. "As in any jungle, the animals will use all the means at their disposal, all their teeth and claws that are permitted by the ecosystem."

Posner, 73, was appointed as a federal appeals court judge by President Ronald Reagan in 1981 and has written dozens of books, including one about economics and intellectual property law.

Posner, who teaches at the University of Chicago, effectively ended Apple's lawsuit against Google Inc's Motorola Mobility unit last month. He canceled a closely anticipated trial between the two and rejected the iPhone maker's request for an injunction barring the sale of Motorola products using Apple's patented technology.

Apple is in a pitched battle with its competitors over patents, as technology companies joust globally for consumers in the fast-growing markets for smartphones and tablet computers.

Posner said some industries, like pharmaceuticals, had a better claim to intellectual property protection because of the enormous investment it takes to create a successful drug.

Advances in software and other industries cost much less, he said, and the companies benefit tremendously from being first in the market with gadgets - a benefit they would still get if there were no software patents.

"It's not clear that we really need patents in most industries," he said.

Also, devices like smartphones have thousands of component features, and they all receive legal protection.

"You just have this proliferation of patents," Posner said. "It's a problem."