June 12 (Bloomberg) -- Citigroup Inc., the world's biggest financial firm, said it increased its stake in Nikko Cordial Corp. to 69 percent from 62 percent, taking full control of the broker.

Citigroup acquired the additional shares from the market and other sources as of June 6, the company said in a filing to the Ministry of Finance today. It spent 117.3 billion yen ($960 million) buying the extra stock, said Mika Nemoto, a spokeswoman for the bank. It now has voting rights of 68.2 percent.

The New York-based bank needed to raise its stake to two- thirds to be able to merge or sell units without the consent of other shareholders. Chief Executive Officer Charles Prince, under pressure from investors to boost profit and the company's share price, gained more than 100 branches in Japan from the Nikko acquisition, adding to purchases in China and Taiwan over the past six months.

Citigroup bought majority control of Nikko for $7.7 billion in April after the Japanese company avoided being delisted because of an accounting scandal. It stated then it intended to increase its holdings to give it full control. Six board members resigned after the country's securities watchdog on Dec. 18 said Nikko overstated earnings for the year ended March 2005.

Citigroup's Japan President Douglas Peterson and Vice Chairman Stephen Volk will join the board of Nikko Cordial Corp. on June 22. The increased shareholding will give the U.S. bank full management control, which includes making the unit into a wholly owned subsidiary.

Citigroup said last week that Brandon Ginsberg resigned as co-head of equities at its Japanese investment bank, as it integrates Nikko.

The departure was the second change of senior managers announced at the unit since Citigroup bought its majority stake in April. The New York-based bank has gained 30 trillion yen of client assets and about 12,000 employees in Japan from buying Japan's third-largest broker.

To contact the reporter on this story: Takahiko Hyuga in Tokyo at thyuga@bloomberg.net

Last Updated: June 12, 2007 06:03 EDT