NEW YORK (Reuters) - Citigroup Inc (C.N) has asked the U.S. Treasury for permission to pay special bonuses and is looking for ways to free an energy-trading unit from government restrictions, the Wall Street Journal reported on its website on Tuesday.

Citigroup Chief Executive Vikram Pandit asked Treasury Secretary Timothy Geithner earlier this month to be allowed to pay stock-based bonuses to employees but the government has not made up its mind yet, the paper reported.

Citigroup executives are describing these as retention bonuses, but the bank is still considering several options of how to structure any bonuses, the paper said.

In one plan, the bonus would be largely stock that vests over some three years and be worth at least half the employee's cumulative pay over the last three years, the paper reported.

Citigroup is also dealing with people threatening to leave from its energy-trading unit, Phibro, because of pay restrictions, the paper said.

Citigroup is looking into possibilities, including either spinning off Phibro into an independent hedge fund or bringing in outside investors, the paper said.

A Citigroup spokesman could not immediately be reached for comment. A U.S. Treasury spokesman declined to comment.