(Adds details on Kroton's possible hostile bid)
By Juliana Schincariol
RIO DE JANEIRO, June 27 (Reuters) - At least 52 percent of shareholders in Brazilian for-profit college operator Estácio Participações SA have voiced their support for rival Kroton Educacional SA's unsolicited, all-stock bid, which could become hostile "if necessary," a source with direct knowledge of the situation said on Monday.
The source, who requested anonymity due to the sensitivity of the issue, said the offer, which values each share of Estácio at the equivalent of 1.25 share of Kroton, is final. The source did not identify the shareholders who have endorsed Kroton's proposal.
The companies declined to comment. Kroton, the world's biggest for-profit education company by market value, announced the plan to take over Estácio on June 2.
Going hostile would depend on how Estácio's board responds to the Kroton bid, the source added, without elaborating. Some of Estácio's larger holders, such as OppenheimerFunds Inc, could demand a shareholder assembly to discuss the proposal without consent from the board, the source said.
OppenheimerFunds, which owns about 5 percent of Kroton, did not have an immediate comment.
The fight for Estácio, a company with about 588,000 students and annual revenue of 4.3 billion reais ($1.3 billion), is rapidly becoming the fiercest unsolicited takeover battle yet in one of Brazil's fastest-growing industries. Estácio is also the subject of a cash and stock merger proposal by smaller competitor Ser Educacional SA.
Earlier on Monday, Estácio said No. 2 shareholder, the Zaher family, will submit a buyout proposal that would give them a majority stake in the company. The Zahers want at least 50 percent of Estácio plus one share and no more than 75 percent of the company - a key requisite to keep it listed on the São Paulo Stock Exchange.
The price and terms of Zaher's proposal were not disclosed. The Zahers decided to vote against Kroton's bid. Estácio named Chaim Zaher, the family's patriarch, as chief executive officer on June 17.
Estacio's board plans to meet on Thursday, the day Kroton's offer expires, to discuss the bids, a second source with knowledge of the matter said.
Shares of Estácio closed 1 percent down at 16.30 reais, while Kroton shed 1.3 percent to 13.74 reais on Monday.
Ser Educacional's bid could still be improved, the company's CEO, Jânyo Diniz, told Reuters last week. ($1 = 3.3895 Brazilian reais) (Writing by Guillermo Parra-Bernal and Tatiana Bautzer; Editing by Dan Grebler and Matthew Lewis)