STOCKHOLM (Bloomberg) ? Frontline Ltd., the world's biggest oil-tanker company, will give shareholders almost half of its stake in Ship Finance International Ltd., worth about $400 million, to promote trading in the stock.

Investors will get one Ship Finance share for every four Frontline shares they own, the Hamilton, Bermuda-based company said on Friday in a statement. The spin-off accounts for about 25 percent of Ship Finance, the owner of most of the oil tankers run by Frontline.

"The spinoff will hopefully lead to an increased liquidity, more independence, better coverage, higher interest and, hopefully, improved pricing of the Ship Finance shares," Frontline Chairman John Fredriksen said in the statement.

In New York, 292,300 Ship Finance shares traded as of 1.18 p.m., less than one-fourth the 1.31 million Frontline shares that exchanged hands. Frontline in June spun off Ship Finance, seeking a higher combined value for the companies. Ship Finance took over 47 tankers from its parent and leased them back at a fixed rate.

Frontline shares rose $1.48, or 3.1 percent, to $48.50 a share in New York at 1:04 p.m. They have more than doubled in the past year, valuing the company at $3.6 billion.

Ship Finance was up 48 cents, or 2.3 percent, to $21.48, bringing the gain since June 14 to 78 percent. The company is valued at $1.62 billion.