UPDATE 1-SK Energy to use 60 pct double-hulled vessels in '08

(Adds details)

SEOUL, April 25 (Reuters) - South Korea's SK Energy (096770.KS) said it will increase its use of double-hulled oil tankers to 60 percent this year, up from 51 percent in 2007.

The move comes ahead of the refiner's plan to ban use of single-hulled vessels from 2010, a year ahead of the government's new deadline.

South Korean refiners have been under pressure to use double-hulled tankers more than economic single-hulled vessels after the country's worst oil spill in December.

Earlier in the year, GS Caltex, South Korea's second-biggest refiner, had said it would ban such tankers from next year.

Industry sources said the decision to ban single-hulled vessels could sound the death knell for such tankers, used predominantly throughout Asia, lifting crude oil freight markets as charterers turn to more double-hulled tankers.

Refiners in South Korea, the largest discharge area for single-hulled very large crude carriers (VLCCs), had agreed to reduce the proportion of such tankers used for their crude imports to 42 percent by the end of the year from the current 52 percent. That would fall further to 30 percent next year.

About 25 percent of the world's single-hulled supertankers usually unload in South Korea. Of the 437 VLCCs that entered the ports of South Korea in 2007, 229 of them were single-hulled, according to Seoul's maritime ministry.

In December Hong Kong-based single-hulled tanker Hebei Spirit was involved in South Korea's worst oil spill, leaking some 10,500 tonnes of crude oil after a crane mounted on a barge punched holes in its hull.

The discharge was about a third of the size of the 1989 Exxon Valdez spill of crude oil onto Alaskan shores, the costliest on record. (Reporting by Angela Moon; Editing by Keiron Henderson)