Global miner BHP Billiton dismissed talk on Thursday that its iron ore partner, Rio Tinto , was baulking at their proposed $116 billion joint venture and said they were close to a binding agreement.

Rio Tinto and BHP Billiton , the world's second and third largest iron ore producers respectively, plan to combine their Australian iron ore operations, aiming to save around $10 billion a year on capital and production costs.

Responding to media reports that Rio Tinto was getting cold feet over the deal, struck in June when Rio Tinto's share price was 25 percent lower, BHP Billiton Chairman Don Argus denied that commitment to the deal had been weakened.

That's not the case within both parties. And that's certainly not the case from a majority of shareholders. They want to see this go through, he told the group's annual meeting.

The companies expect to have the main submissions on the joint venture to regulators by the end of this year, Chief Executive Marius Kloppers said, adding that the main terms of the agreement should be hammered out shortly.

By the end of this year we would like to be in the position where the definitive agreements have been concluded, where required submissions to regulators have been done, he said.

Kloppers also said BHP Billiton was close to a decision to either sell or restart its huge Ravensthorpe nickel mine and processing operation in west Australia.

Ravensthorpe at peak capacity would produce about 55,000 tons of nickel a year, roughly equal to about 5 percent of annual global output of the metal, used to make stainless steel.

The company closed Ravensthorpe in January after a steep slide in the nickel price. The price has since regained some ground, but BHP Billiton still does not regard this as one of their core growth assets and has received several bids.

Australian nickel miner Minara Resources Ltd and Metallurgical Corp of China <601618.SS> <1618.HK> submitted a bid before Wednesday's offer deadline, according to a source with direct knowledge of the bid and also media reports.

First Quantum Minerals of Canada are also interested in Ravensthorpe but it remains unclear whether it too made an offer, media reports said.

(Additional reporting by James Regan; Editing by Mark Bendeich)