Patent requests in the Europe reached a record high in 2011, in a telling sign that companies are determined to stay on the cutting edge despite a debt crisis and an uncertain economy.

In total 244,437 requests for patents were filed in 2011 at the Munich-based European Patent Office, the body's annual report showed. That is 3.7 percent more than 2010.

The office, which centralises requests from 38 European nations, maintains a strict qualitative control and on average approves four requests out of 10. In 2011, the office approved 62,115 patents, 6.9 percent more than 2010.

"Companies have responded very differently (to the crisis) than in 2008-2009 when we saw a huge drop (in requests)," said EPO president Benoit Battistelli.

"The financial crisis is still here, but the vast majority of businesses have decided to not sacrifice research and development investment," he said.

Companies "have absorbed the idea that to develop advantages in an increasingly globalised world, and where new competitors arrive in force, innovation must be maintained," Battistelli said.

"Patents are the the most effective way to do that," he said.

For world tech giants, patents have become a key battleground and companies now defend their technology in courtrooms around the world, brandishing patents as their claim to new riches.

Internet giant Yahoo! this month filed a suit against Facebook in a California court, accusing the social networking giant of infringing on 10 patents.

Microsoft and Apple last month filed complaints with the European authorities against Google's Motorola Mobility in an increasingly bitter patent war between technology giants.

Apple is already embroiled in a multi-continent patent fight with South Korea's Samsung.

"These court cases are spectacular in terms of the sums involved, but we can't say there are more (court cases) today than before," the EPO chief said.

"But when you are aiming to dominate the world mobile phone or smartphone market, the economic and financial stakes are so great that all means available are used," Battistelli said.

"Fundamentally, this shows that patents have become a strategic tool for companies," he noted.

"If we have companies that are willing pay tens of millions of dollars to buy patents, then patents have a greater strategic value."

Based in Munich, the office employs 7,000 people on a budget of 1.7 billion euros ($2.26 billion).

But 62 percent of requests come from outside Europe, with a quarter coming from the United States alone and with Asia playing an increasing role. China and Korea together accounted for 32 percent of requests last year.

This is no surprise to Battistelli.

With Asia becoming more global, China in particular is becoming "more and more an economy of innovation", he said -- so much so that China overtook France in patent requests last year, applying for 16,946 patents, up from a mere 160 in 2000.

In Europe, Germany leads patent activity with 33,181 requests, ahead of France's 12,107 requests.

Siemens made the most patent demands with 2,235 requests, ahead of Netherlands-based Philips and Korea's Samsung.

Patents in 2011 chiefly concerned medical technology, followed by electric machinery, energy and computers.

Earlier this month, the World Intellectual Property Organization said global patent filings also set a new record in 2011 with annualised growth of 10.7 percent.