Jan. 16 (Bloomberg) -- Citigroup Inc.’s commodities-trading unit hired a second vessel for storing crude to profit from higher prices later in the year, shipbrokers said.

Phibro LLC booked supertanker Ashna to store crude for as many as three months, according to the reports by SeaLeague AS in Oslo and Athens-based Optima Shipbrokers. The tanker was booked for storage on the U.S. Gulf Coast, SeaLeague said. Citigroup spokesman Jeffrey French declined to comment.

Phibro is also storing North Sea Forties crude on a 1 million barrel vessel off Scotland’s Orkney Islands. Royal Dutch Shell Plc and BP Plc are keeping crude on vessels to profit from so-called contango, a market where buyers pay more for delivery later in the year than today. A purchaser buys oil now, keeps it for months at sea, and sells oil futures that are higher than the spot price.

Shell, Europe’s largest oil company, hired a supertanker earlier this week to store crude off the U.K. coast, according to shipbrokers. Morgan Stanley is also seeking a vessel to store crude, four shipbrokers said yesterday.

Traders have hired tankers to store at least 15 million barrels of North Sea oil, according to the median estimate of six North Sea traders and analysts surveyed this week. As many as 80 million barrels of crude are being stored at sea globally, Frontline Ltd., the largest owner of supertankers, said yesterday.

To contact the reporter on this story: Alexander Kwiatkowski in London at akwiatkowsk2@bloomberg.net; Alaric Nightingale in London at Anightingal1@bloomberg.net

Last Updated: January 16, 2009 07:53 EST