The Mediterranean region, the battleground of empires for millennia, is now the arena for a new kind of rivalry as global energy giants move in following major natural gas strikes and the political upheaval of the Arab Spring.

"There are a lot more opportunities than there were before the Arab Spring in places like Egypt, Libya and Tunisia," where longtime dictators were toppled in 2011, says Bill Higgs, chief executive officer of exploration firm Mediterranean Oil and Gas.

But, observes the Financial Times, "it was the big finds in the Mediterranean that fundamentally changed the industry's view of the region" in 2009-11.

The U.S. Geological Survey estimates the Levant Basin in the eastern Med alone contains 122 trillion cubic feet of natural gas and 1.7 billion barrels of oil.

The oilmen risk entanglement in some of the world's most intractable disputes -- the Arab-Israeli conflict and the age-old rivalry between Turkey and Greece, particularly over Cyprus, divided since Turkey invaded in 1974 and seized the northern part of the eastern Mediterranean island.

The tiny island of Malta is in dispute with nearby Libya over offshore exploration zones that are likely to hold sizeable volumes of gas and oil.

Lebanon accuses neighboring Israel of encroaching on its maritime economic with its recent major gas strikes.

Israel has found the largest gas fields under the Mediterranean to date -- around 30 tcf, worth around $240 billion at today's prices. It's likely to outstrip Egypt and other Mediterranean states in production terms within two years.

Houston company Noble Energy Inc., which spearheaded the Israeli exploration, and its partners have discovered enough gas to supply the Jewish state's requirements for as much as 150 years at the current rate of consumption.

Leviathan, off Israel's northern coast, is by far the biggest field, containing an estimated 25 tcf. It's expected to start production by 2016. The nearby Tamar field holds around 8 tcf.

Noble's CEO Charles Davidson said in July the Texas outfit is seeking a partner for a planned liquefied natural gas terminal, which could cost $5 billion.

Off nearby Cyprus, Noble has already made a sizeable strike in the Aphrodite field that's considered an extension of Leviathan, and there are plans to combine Israeli and Cypriot exports to Europe via Greece.

Gazprom, the Russian energy giant, is making major efforts to secure a piece of the East Med action. Moscow, determined to restore its Cold War influence in the region, is dangling major bailout deals for the economically troubled Greek Cypriot government, which controls the exploration zones off the south coast.

In Egypt, BP is due to initiate deep-water gas exploration in Egypt's Mediterranean Basin this month. Chief executive Robert Dudley says BP will invest $10 billion over the next five years.

Egypt's proven gas reserves are pegged at 77 tcf, the third highest in Africa after Nigeria and Algeria. BP's offshore project is expected to boost that by 20 percent.

BP Egypt announced Aug. 26 it had made two new strikes in the Nile Delta, raising the area's total to five.

BP is expected to start its much-delayed deepwater drilling in Libya's Gulf of Sidra, a major oil-producing region, in 2013. It suspended the controversial $900 million program during Libya's civil war in 2011 that ended with the death of longtime dictator Moammar Gadhafi.

The new government, still grappling with major security problems, has restored much of Libya's energy infrastructure, damaged or shut down during the conflict, and almost reached the pre-war production of 1.6 million barrels a day.

But Libya's believed to have richer prospects, and BP's offshore operation is seen as a potential gamechanger.

Algeria avoided much of the Arab Spring turmoil, but the military-backed government has been forced to introduce major reforms to head off trouble and open up the all-important oil and gas sector.

State oil company Sonatrach is soon to sign agreements with Royal Dutch Shell and Exxon Mobil Corp. on shale gas exploration. It already has similar deals with Eni SpA of Italy and Canada's Talisman Energy Inc.

Italy recently relaxed a ban on drilling in coastal waters imposed after BP's 2010 Deepwater Horizon disaster in the Gulf of Mexico.

The Financial Times reports "a clutch of companies are dusting off plans to drill in the Adriatic," among them Edinburgh company Petroceltic that's slated to resume drilling in 2013.