"The mainstream view is certainly that $50 is not the price to be basing on for exploration investment. But that price band has been rising in the past 12 months or so," Mobed told Reuters in a telephone interview.

Explorers were now looking at $30 or $40 a barrel of oil as the base for investment rather than $15 or $20 a few years ago, he added.

IHS Energy, which primarily deals in upstream oil research, consulting and software to oil firms and producing nations, recently bought Cambridge Energy Research Associates (CERA), the energy analysis firm run by Daniel Yergin.

Mobed, who joined IHS Energy six months ago after 22 years at engineering and service firm Schlumberger, said the message IHS got from its customers was that spending was definitely going up.

"We are starting to see the ship has started to turn now. People are really thinking this is the real time to expand their exploration budget in a meaningful way," he said.

But he said the industry has far more discipline now than five to 10 years ago.

"It has matured into a business much more careful about matching its investment to the cycles, thinking about whether the investment opportunity is there in a relative turbulent price regime."

U.S. light crude futures has soared so far this year by 68 percent, having rocketed by $20 in less than four months, lately spurred on by U.S. Gulf of Mexico producing outages that has exacerbated a global shortage of light, low-sulfur crude.

Analyst Wood Mackenzie said earlier this month that energy majors will add more than three million barrels of crude oil to daily production in the five years to 2008.

Gas production was also expected to grow, by about one million barrels of oil equivalent (boe) to 9.1 million boepd over the same period.