SAO PAULO, Aug 31 (Reuters) - Brazilian lender Itau Unibanco said on Wednesday its board approved a plan to have greater sway over its credit card subsidiary Itaucard SA.

Itau, Brazil's largest private lender, has proposed taking over some of Itaucard's key business activities, such as issuing and managing credit cards, managing payments and loyalty programs, as well as financing vehicles.

In turn, Itaucard will retain control of offering and maintaining payment accounts, financial investments, securities, derivatives and other credit assets.

The proposal is set to be voted on at the shareholders' meeting scheduled for Sept. 30.

As part of the plan, a segment of Itaucard will be spun-off into a separate vehicle, which will then be incorporated by the parent company. (Reporting by Peter Frontini and Carolina Pulice, Edited by Isabel Woodford and Chris Reese)