Vale is negotiating BHP exit from Samarco venture -source‍​

(Adds details on possible deal, context)

SAO PAULO, Jan 3 (Reuters) - Vale SA is in talks with BHP Billiton Ltd over the future of their joint venture, Samarco Mineração SA, and one alternative is for the Brazilian miner to buy out its partner, a source with knowledge of the matter said on Wednesday.

A price has not yet been established for any buyout and it would depend on BHP's willingness to exit the venture, said the person, who spoke on condition of anonymity because the negotiations are private.

Contacted by Reuters, Vale (Swiss: VALE.SW - news) and BHP declined to comment. ‍​

Samarco has not operated since November 2015 after flood waters inundated a dam designed to hold back mine waste, causing it to burst and flood nearby towns. Nineteen people were killed in what was Brazil's worst environmental disaster.

Vale thinks that Samarco can return to operating sooner speed up remediation works if it had a sole owner, the source said. Last month, Samarco won preliminary permits, but is not yet allowed to restart.

The deal depends on BHP's willingness to exit, the source added. Samarco is the only iron-ore operation owned by BHP outside Australia. (Reporting by Tatiana Bautzer in Sao Paulo, Marta Nogueira and Alexandra Alper in Rio de Janeiro and Tom Westbrook in Sydney; Editing by Leslie Adler and Grant McCool)