(Corrects headline to read Mubadala instead of Mubdala)

SAO PAULO (Reuters) -Zamp, the owner of the Burger King brand in Brazil, said on Tuesday its shareholders rejected a proposal to include a poison pill in its internal bylaws, a win for Abu Dhabi state investor Mubadala which is building a large stake in the firm.

The proposal that would implement a poison pill in addition to limit the voting power of a single shareholder to 15% was rejected 57.5% of the votes, Zamp said.

The outcome is a key win for Mubadala, who raised its stake in the firm to 20.4% shortly after the proposal was unveiled in July, becoming Zamp's largest shareholder.

Last year, the Abu Dhabi sovereign investor had already tried to take over Zamp, but withdrew a tender offer it had launched saying it failed to confirm whether the deal would imply the termination of the firm's franchise and trademark licensing agreements.

At the time, Mubadala had 4.95% of the company and it offered 8.31 reais per share to buy a controlling stake. Zamp's shares rose 1.65% on Thursday to 5.55 reais.

(Reporting by Peter Frontini; Editing by David Gregorio)