CITIGROUP INC. 
Michael Parroy, a lawyer for the SFO, told London's Old Bailey criminal court the former UBS (>> UBS Group AG) and Citigroup (>> Citigroup Inc) trader's assets included a seven-bedroom country house in southern England.
Parroy, opening an expected three days of arguments over Hayes's assets, said others included Hayes's wife Sarah Tighe's engagement ring, wedding rings and other jewellery and gifts made to friends and family.
"Mr Hayes was far and away the dominant earner" for the couple between 2006 and 2010, Parroy said, when Hayes worked in Japan as a highly successful yen derivatives trader, earning bonuses and incentives of around 2.45 million pounds.
Parroy alleged Hayes manipulated Libor to give himself a financial advantage and build a reputation as "the top man in a relatively small pond" of traders, which made him an attractive target for other banks and a valuable commodity for UBS.
Hayes is due to give evidence on Wednesday.
His lawyer did not make an immediate response to a Reuters request for comment.
Hayes was found guilty last August of conspiring to rig Libor - a benchmark used to set rates on hundreds of trillions of dollars worth of contracts and loans worldwide. He has been transferred to London's Belmarsh prison from Lowdham Grange in Nottingham to attend court with his wife.
The SFO cast Hayes as the ringleader in a wide-ranging conspiracy to rig yen Libor. But six former brokers named as his alleged co-conspirators were cleared of the crime by a jury in January.
Hayes, 36, who has been diagnosed with mild Asperger's syndrome, appeared agitated during the court session on Tuesday and frequently passed notes through the gaps in the glass-walled dock to his legal team.
He made around $300 million for UBS over three years before he was lured away to Citigroup in 2009 with a 2.2 million-pound bonus, the court heard during his original trial. But Citigroup sacked him in 2010 for attempted rate-rigging as a global inquiry swung its focus on how yen Libor rates were set.
TAINTED GIFTS
Parroy said Hayes and his wife jointly bought the 1.2 million pound Old Rectory in Surrey, southern England, in 2011 from Hayes's "accumulated cash reserves".
But when Hayes was arrested in December 2012, charged by U.S. prosecutors and began cooperating with the SFO in 2013 in the hope of avoiding U.S. extradition, his assets were frozen.
To raise funds, the couple tried to sell the house but, when that failed, Tighe returned to work as a corporate lawyer after maternity leave and took out a buy-to-let mortgage secured on her share of the house.
Hayes had been charged by UK prosecutors with conspiracy to defraud in June 2013, six months after also being charged by U.S. prosecutors with fraud related offences. In July, the property was transferred into Tighe's name, the court heard.
Parroy alleged Hayes made a "tainted gift" of his share of the house, which he alleged was worth roughly 2.0 million pounds. Parroy alleged that Tighe paid roughly 600,000 pounds less for the 50 percent share than it was worth.
(Reporting by Kirstin Ridley; Editing by Jane Merriman, Greg Mahlich)
By Kirstin Ridley
