Citigroup ( C) plans to sell its 26% stake in Japanese online broker Monex Group as part of the bank's global efforts to raise cash, Reuters reports, citing a story by the Yomiuri newspaper. Citigroup's stake in Monex was worth about 15.3 billion yen ($156 million) as of the close of trading Thursday. Monex is Japan's third-biggest online brokerage. A spokeswoman at Citigroup's Japanese investment bank unit, Nikko Citigroup, declined to comment on the report, according to Reuters. Citigroup appears to already have sounded out several financial institutions on the sale of its stake in Monex, the Yomiuri reported. Other Internet-based brokerages and large financial institutions looking to beef up their retail businesses could be interested in the stake. Citigroup also is trying to sell its Japanese retail brokerage unit, Nikko Cordial, according to previous published reports. Some top Japanese banks could be interested in buying a stake in Monex, Reuters reports, citing analysts.