AP Photo: Mark Lennihan

NEW YORK (AP)—Morgan Stanley plans to increase its majority stake in Morgan Stanley Smith Barney Holdings LLC, adding another 14 percent of its shares.

The investment bank said Thursday that it has told Citigroup Inc. that it plans to exercise its right to make the purchase on Friday. The price will be determined over a period of up to 90 days.

Morgan Stanley currently has a 51 percent stake in the joint venture.

Morgan Stanley Smith Barney is a wealth management company whose products and services include brokerage and investment advisory services, financial and wealth planning, credit and lending, cash management, annuities and insurance, retirement and trust services.

Morgan Stanley and Citi agreed in January 2009 to combine Morgan Stanley’s wealth management unit with Citi’s Smith Barney brokerage division. Morgan Stanley paid $2.7 billion to Citi as part of the deal.

Shares of Morgan Stanley rose 8 cents to $13.17 in midday trading Thursday. Its shares have traded in a 52-week range of $11.58 to $24.49.