Europe’s threat to ban cargoes from Iran was helping push Middle East oil-tanker hiring to a record on concern shipments from the region will be disrupted, consultant FACTS Global Energy said.

The CHART OF THE DAY shows how oil tankers booked to load 2 million-barrel cargoes of Persian Gulf crude climbed to 140 in December, the most since at least January 2005, according to data from London-based shipbroker Galbraith’s Ltd. European Union foreign ministers will meet Jan. 30 to discuss possible sanctions to pressure Iran.

EU Energy Commissioner Guenther Oettinger said Dec. 6 the 27-nation bloc may have reached a consensus on imposing a ban. Greece blocked the measure at a summit on Dec. 1.

“Fear of potential Iranian sanctions has contributed greatly to the increased shipments from the Persian Gulf,” adding to seasonal gains in the last two months of the year, said FACTS analyst Roy Jordan, previously an oil trader at Royal Dutch Shell Plc, where he worked for more than 30 years. “Some of the refiners around the world are undoubtedly beginning to get a little bit concerned about a reduction in exports.”

Oil traded in New York climbed the most in almost a month on Dec. 13 after a report said Iran would hold military drills in the Strait of Hormuz, a shipping lane handling a fifth of the world’s crude shipments. Cargoes from the Persian Gulf grew 13 percent this year as demand from Asian refineries accelerated.

However, experts say “some of the engines of global growth” depend on Iranian oil and warn that any sanctions on Iran’s oil exports will lead to an oil price shock.

Some of the engines of global growth depend on Iranian oil: 6% of Chinese oil imports come from Iran, 9% of India’s and 10% of South Korea’s. In addition, Iranian oil makes up 30% of all Greek oil imports and 7% of Japan’s, according to the Financial Post.

The U.S. Congress last week passed a bill that included provisions that would impose sanctions on foreign financial institutions that do business with Iran’s central bank. The U.S. and its European allies are also mulling sanctions against Iran’s oil exports.

JPMorgan Chase & Co. fears Iran may try to shock the global economy by cutting off oil supplies altogether.

“If Iran sees a loss of income as inevitable, there is a greater risk that it takes what limited political and economic capital it has to the negotiating table by invoking a pre-emptive export ban,” said Lawrence Eagles, an analyst at JPMorgan.

“The EU sanctions are not a done deal,” says Ms. Spector of CIBC, adding that apart from Europe, Iran’s key Asian clients such as Japan obsess too much about energy security to cut off Iranian supplies.

The Greeks have raised doubts about an EU oil ban, while Japan and South Korea are reportedly seeking a possible waiver to U.S. legislation. Meanwhile, China could exploit the situation to demand better pricing for Iranian oil.

Not surprisingly, while most analysts see Iran as an “upside risk,” most believe the global oil market will continue to meander.

“The key upside risk is supply disruption from Iran, or an anticipation thereof, which would add a risk premium to the price. In our forecast we assume that the current level of tension rumbles on without solution, but also without escalating,” says Helen Henton, an analyst at Standard Chartered Bank.

Iran’s oil revenue is expected to rise by a third this year to $100 billion, according to energy consultants IHS CERA.

Not surprisingly, oil prices have simmered on tensions in the Middle East despite prospects of an EU recession in 2012. Canadian Imperial Bank of Commerce, which has issued the most bullish crude forecast among major banks, expects Brent to average around $123 in the new year, with U.S. crude closing its spread differential too.

“However, if the Strait of Hormuz is impacted, all bets are off,” said Katherine Spector, energy analyst at CIBC.

The Strait of Hormuz is the narrow seaway through which oil is shipped not just from Iran but other Middle East states too. The London-based Centre for Global Energy Studies estimates 14% of global crude-oil production could be at risk if the vital waterway was to become unnavigable, “an event that would no doubt cause an immediate and severe spike in the price of oil in 2012.”

The result could be catastrophic. Oil prices could jump $23 a barrel in the first few weeks of the conflict and by a jaw-dropping $175 if it persists, according to a survey of energy traders by Rapidan Group, a Washington-based consultancy.