Citigroup is pursuing its option to buy back its own headquarters, found in Manhattan's Tribeca neighborhood at 388-390 Greenwich Street. As it turns out, the option to buy the office complex for $2 billion was part of an earlier agreement with its landlord, SL Green Realty Corp.

According to Bloomberg, the New York-based company will be able to complete their purchase of the office complex by December 2017, as noted by SL Green in its fourth-quarter statement on Wednesday.

The buyback option was apparently part of a deal made almost ten years ago, when Citigroup previously sold the property in a partnership between New York City's largest office landlord, SL Green, and Ivanhoe Cambridge. The Real Deal reports:

"The banking giant will buy back the 2.7 million-square-foot office complex it sold to a partnership between SL Green and Ivanhoe Cambridge for nearly $1.6 billion in 2007. The bank signed a $1 billion lease renewal for its 2.7 million square feet at the properties in 2013 - a deal that came with the $2 billion buyback option."

Furthermore, it was back in 2014 when SL Green acquired Ivanhoe Cambridge for $783 million, just to take full control of the property, which is currently going through a huge renovation, and under full wraps.

Apparently, Citigroup has long been trying to consolidate its office into the Greenwich Street complex, even foregoing its headquarters on 399 Park Avenue.

Citigroup currently leases 2.63 million square feet at 388-390 Greenwich Street, which SL property and a subsidiary of Caisse de Depot et Placement du Quebec acquired from the bank for $1.58 billion in 2007.

As SL Green released its year-end earnings for 2015, the company also revealed one of its most prolific leasing transactions: a 23-year, 43,000-squaref-foot deal with Nordstrom, which plans to obtain three retail levels at 3 Columbus Circle, which the REIT owns in partnership with the Moinian Group.