Citigroupplans to sell its 26 percent stake in Japanese online broker Monex Group as part of the struggling U.S. bank's global efforts to raise cash, the Yomiuri newspaper reported on Friday.

Citigroup's stake in Monex was worth about 15.3 billion yen ($156 million) as of Thursday's close but shares in the firm,  Japan's third-biggest online brokerage, dropped 5.7 percent after the report.