Citi trader Andrew J. Hall's German castle and store of some of his art collection, Schloss Derneburg. Its history dates back almost a thousand years. Originally a fortified castle, by the twelvth century it had become the manor house of Margrave Herman II von Winzenburg and his brother Heinrich, vassals of Graf Burchard I von Locum. Hermann feuded with Burchard and in 1130 arranged to have him murdered. Unfortunately for Hermann, Burchard was a close friend of Kaiser Lothar III and the latter had the von Winzenburgs forfeit their properties as punishment. Derneburg was assumed by the Bishopric of Hildesheim with the stipulation that a religious sanctuary should be founded there. Thus began Derneburg's new role as the home of various religious orders, a role it played for nearly seven hundred years.

The Wall Street Journal reports that a top Citi energy trader is pressing the financial giant to honour a 2009 pay package that could total $100 million, setting the stage for a potential showdown between Citi and the US government's new pay czar.

The trader, Andrew J. Hall, heads Citigroup's energy-trading unit, Phibro LLC -- a secretive operation, run from the site of a former Connecticut dairy farm, that occasionally accounts for a disproportionate chunk of Citigroup income.

Hall and his small team of traders take 30% of Phibro's profits and in recent years, he has earned several hundred million dollars.

The Journal says Hall's pay package puts Citigroup in a tight spot. Ripping up the contract could trigger Hall's departure and a potentially messy legal fight. But making any large payouts, even if they're based on previously agreed contracts, could subject Citigroup to political and investor fallout.

Hall is contractually obligated to receive pay based on Phibro's profits, and some observers on Wall Street believe Citigroup has a better chance at repaying the US money with its Phibro unit humming.

The Journal says critics, however, argue that pay agreements like these need to be redrawn in light of Citigroup's taxpayer-funded bailout. Soon the US government will be a 34% owner of Citigroup.

Citigroup said in a statement: "Retaining and attracting the best talent is very important to the success of Citi and all its stakeholders. Citi continues to examine ways to ensure its employee-compensation practices are competitive in this very challenging market environment."

In recent years, as Citi struggled with toxic mortgage-related assets, Hall's bets on oil and gas delivered hundreds of millions in profits for the struggling financial firm.

In Las Vegas, gamblers can lose their shirts and the collateral damage is usually limited. However, with trading income and associated risk being a big potential source of income for the big financial firms, who have a guarantee of protection form the US taxpayer, the government has yet to devise a system which would limit the risk from the casino players on Wall Street.

The British-born Hall lives in the Connecticut town of Southport, where in recent times, he waged a four-year battle with the neighbours to place "Etroits sont les Vaisseaux," or "Narrow Are the Vessels," an 80-foot-long concrete sculpture, on the lawn of his Greek Revival home.