Citigroup's (C) London HQ Put on the Block

The European headquarters of Citigroup (NYSE:C), based on London, has been put up for sale with an asking price of $1.63 billion, or £1 billion.

Irish real estate company Quinlan Private, owner of the property, paid £1 billion for the property in 2007.

The office tower has Citigroup as its only occupant, and is 42-stories high.

Citigroup has a 24-year lease on the property, and pays about $94 million a year for rent, which will increase in 2015.

Citigroup was trading at $4.53, falling $0.03, or 0.55 percent, as of 1:57 PM EDT.