UPDATE 1-Bain finalising $1.1 bln deal to buy Citi's Bellsystem

* Largest foreign private equity deal in Japan in almost 2 yrs

* Bain outbids Permira, CVC Capital and Blackstone-sources

* Official announcement could be made in next few days-sources

By Junko Fujita and Megan Davies

TOKYO/NEW YORK Nov 13 (Reuters) - Bain Capital is finalising a roughly 100 billion yen ($1.1 billion) deal to buy Japanese telemarketer Bellsystem24 from Citigroup Inc (C.N), three sources familiar with the the matter said, in the largest buyout by a foreign private equity firm in Japan in nearly two years.

Bain has outbid Permira [PERM.UL] and a team of CVC Capital and Blackstone (BX.N), which had also made offers in the final round of bidding for Bellsystem24, the people said, speaking on condition of anonymity because the talks are not public.

Bain is working on the final details and an official announcement could be made within the next few days, the sources told Reuters.

"A deal is imminent," one of the sources said.

Bain had been tipped as the likely buyer when it secured exclusive negotiation rights earlier this month. [ID:nT162593]

But the door was thought to be still open to the other bidders after the deadline for Bain's exclusive rights passed on Nov. 6 and no deal had been announced.

Talks had been ongoing with the CVC and Blackstone team after the exclusivity period ended, and that team had improved its bid, one source familiar with that move told Reuters.

Citigroup put Bellsystem24 up for sale as part of a global effort to raise cash and replenish its capital. The U.S. bank has already raised more than $7 billion by selling other Japan assets including a broker, a trust bank and a fund management arm.

The sale of Bellsystem24 initially drew strong interest from a number of private equity firms including Kohlberg Kravis Roberts & Co [KKR.UL], which teamed up with a trading house Itochu Corp (8001.T) before dropping out of the race.

The deal will likely reach or exceed 100 billion yen, sources said, making it the country's largest buyout by a foreign private equity firm since March 2008 when Permira bought agrichemical company Arysta LifeScience Corp for more than $2 billion.

Bellsystem24 is Japan's largest telemarketing firm. It competes against Moshi Moshi Hotline Inc (4708.T) and Transcosmos Inc (9715.T) in Japan. (Reporting by Junko Fujita and Megan Davies; Editing by Chris Gallagher)