Ventana Gold Corp said on Monday it agreed to a sweetened bid from Brazilian billionaire Eike Batista to buy the shares he doesn't already own and which values the company at around C$1.5 billion.

Ventana, which owns the promising La Bodega gold property in Colombia, agreed to the C$13.06-a-share offer after fighting off a C$12.63 hostile bid from Batista's AUX Canada Acquisition Inc for nearly three months.

Ventana shares jumped 4.8 percent in early trade on Monday at C$12.87 per share after touching highs of C$12.92.

The new offer represents a premium of 30.2 percent to the closing price of Ventana's common shares on Nov. 16, just before AUX, formed to pursue the Ventana bid, announced its hostile proposal.

I expected a higher bid actually, but it looks as though the Ventana board with a lack of alternatives decided it was best to support this, said Michael Fowler, senior mining analyst at Loewen, Ondaatje, McCutcheon in Toronto.

It still doesn't preclude other companies from coming in even now, he added.

Batista, already Ventana's largest shareholder with a 20 percent stake, last week said he had no intention of raising his offer for Ventana, which was to expire Feb. 15.

The two parties said on Monday they will work together to finalize an agreement, and AUX will extend its offer beyond the current expiry date. Ventana said its board will support the revised AUX offer.

Ventana's La Bodega gold property promises to become one of the first significant gold mines in Colombia since the nation's new economic and political stability following years of internal strife ushered in a new gold rush.

Batista, one of Brazil's best-known personalities, has been trying to buy Ventana for years to add it to his global portfolio of mining and oil properties.

The first bid was in November 2009, when he made a private offer for C$12 a share plus stock. Last February he offered Ventana shareholders C$10 a share plus stock in a new company.

The day before making his hostile bid at C$12.63 a share, he had proposed a friendly C$13.06-a-share deal, which was rejected at the time.