London • Japan's need for additional energy to replace supply from nuclear reactors that were damaged or shut in the aftermath of the massive earthquake could put pressure on the natural gas market, the finance chief of Royal Dutch Shell, Simon Henry, said Tuesday.

"There's likely going to be a tightening of the liquefied natural gas market ... especially Europe," Henry said during a Shell strategy meeting in London.

Prices of natural gas rose after the earthquake and tsunami, which hit Friday, and a series of explosions this week at a nuclear plant.

Energy companies such as Shell are expected to divert deliveries of liquefied natural gas to Japan from Europe as part of a worldwide relief effort. Some analysts said Britain would be most affected by any reduction in supply because it was Europe's biggest consumer of gas. The price of gas for delivery next winter in Britain rose Tuesday to the highest level since November 2008, according to Bloomberg News.

A report by Bank of America Merrill Lynch said Japan might buy 7.1 million metric tons more of liquefied natural gas a year as a result of the disaster, which caused power cuts in Japan and shut down at least 11 reactors in the country.

Shell CEO Peter Voser said the company was working with the Japanese government to divert energy cargos to Japan. One delivery arrived Monday night in the Tokyo Bay area, he said, but conditions to supply energy in Japan remained complicated.

Analysts said the situation in Japan would probably hang over energy markets for several months. In particular, investors are watching to see if demand for oil falls amid broader uncertainty about economic growth in Japan. Any drop in demand, however, could be partly offset if Japan bought large amounts of crude oil to help make up for the loss of nuclear power.

"Market participants have not fully factored in the effects on oil demand three to six months from now," Chris Lafakis, an energy economist at Moody's Analytics, said.

"They are more concerned about the immediate question of, 'Is there going to be a nuclear meltdown?' "

Qatargas and Rasgas, two state-controlled Qatari natural gas companies, said on Monday that they stood ready to help Japan meet any increased requirements for liquefied natural gas, Reuters reported.

The events in Japan also had an effect on the price of European Union carbon-dioxide permits, which rose amid expectations that energy providers would be forced to burn more fossil fuels to make up shortfalls. The price of crude oil fell as investors expected weaker demand from Japan's earthquake-hit economy.