(Updates with share moves in paragraph 2, deal details...

(Updates with share moves in paragraph 2, deal details throughout and background in paragraph 3, adds executive comments in paragraph 5)

Feb 16 (Reuters) - Australia's Hastings Technology Metals (HAS) said on Friday it will supply mixed rare-earths carbonate from its Yangibana project in Western Australia to Chinese producer Baotou Sky Rock for a minimum period of seven years.

Shares of the Australian rare-earths miner advanced as much as 16.1%, their biggest intraday jump since July 4, 2023.

Hastings, which is backed by Fortescue (FMG) Chairman Andrew Forrest, will supply a minimum of 10,000 tons per annum of concentrate for an initial seven years, with the offtake deal having an option to extend it for another five.

Hastings is developing a rare-earths mine and processing plant at Yangibana in the Gascoyne Region of Western Australia.

"Negotiations are ongoing with other potential customers to conclude similar offtake arrangements for the remaining Yangibana Project volumes," Hastings told investors in a statement on Friday.

The company said the offtake deal will allow it to realise higher prices for its concentrate and would significantly improve the "economics of the Yangibana Project."

Hastings had previously signed an offtake agreement in 2018 with the privately-owned Baotou, which lapsed last year.

The Australian miner also has existing supply agreements with European chemical giant Solvay SOLB.BR and owns a 21.15% stake in Canada's Neo Performance Materials NEO.TO .

In 2022, Forrest's Wyloo Metals made an investment through a note issue to fund Hastings' stake buy in Toronto-listed magnet producer Neo.