(New throughout, adds board meeting to discuss the proposals)
SAO PAULO, June 27 (Reuters) - The board of Estácio Participações SA, Brazil's No. 2 private college operator, will meet on June 30 to discuss three different buyout bids, a source with knowledge of the matter told Reuters on Monday.
A major Estácio shareholder, the Zaher family, offered earlier in the day to buy out minority owners in an effort to outmaneuver two rivals' takeover bids.
Estacio said in a securities filing that the Zahers had submitted a buyout proposal that would give them a majority stake in the company. The Zahers, aiming to keep Estácio listed on the Sao Paulo Stock Exchange, would not buy more than 75 percent of the company.
The proposed price and terms of the Zahers' proposal were not disclosed. The family, which holds a 13 percent stake in Estacio, has decided to vote against a bid from Kroton Educacional SA, the world's largest education company by market capitalization. The Zaher patriarch, Chaim Zaher, was named Estacio's chief executive officer on June 17.
The Zahers are discussing financing with local banks, another source with direct knowledge of the matter said. Shares of Estácio shed 0.8 percent in afternoon trading on the São Paulo Stock Exchange. Kroton shares lost 2 percent.
Kroton improved the unsolicited bid for Estácio by almost a third on June 21. A source familiar with Kroton's plans said last week that the education giant already had the support of about 40 percent of Estacio's shareholders.
Ser Educacional, the third bidder, may still sweeten the terms of a merger proposal sent to Estácio's board on June 5, CEO Jânyo Diniz said last week. It was not clear whether the board would postpone the Thursday meeting if not all competing offers are formalized by then, the source said.
The fight for Estacio, a company with about 588,000 students and annual revenue of 4.3 billion reais ($1.3 billion), is quickly becoming the fiercest unsolicited takeover battle yet in one of Brazil's fast-growing industries.
Kroton's offer, valid through June 30, would swap each Estacio share for 1.25 Kroton shares, valuing the company at around 4.5 billion reais. Under those terms, Estacio shareholders would get about 23 percent of the new company.
Ser Educacional proposed a cash payment and a merger in which Estacio's shareholders would keep 69 percent of the new company. ($1 = 3.39 Brazilian reais) (Reporting by Tatiana Bautzer and Guillermo Parra-Bernal; Editing by Jonathan Oatis and David Gregorio)