* Government yet to accommodate Rio Tinto interest - dep. min.
* Holding company to acquire Indonesia's stake in Grasberg
* Company due to be formalised "today or Monday" (Adds context, earlier comments from Freeport CEO)
By Fergus Jensen and Wilda Asmarini
JAKARTA, Nov 24 (Reuters) - Indonesia's Ministry of State-Owned Enterprises, tipped to oversee an acquisition of a majority stake in the local unit of Freeport-McMoRan Inc , has "no clear structure" yet for the deal, a ministry official said on Friday.
Under a framework agreement announced in August, Phoenix, Arizona-based Freeport said it would divest 51 percent of PT Freeport Indonesia (PT-FI), but there has been little progress since then.
Freeport, operator of Grasberg, the world's second-largest copper mine, also agreed to build a second smelter in Indonesia and to invest up to $20 billion in expansions.
Fajar Harry Sampurno, the deputy minister for state-owned enterprises, said it was not clear yet what role state pension funds and state-owned banks would play in financing the acquisition, amid ongoing discussions on the matter with the Ministry of Finance and Freeport.
Sampurno added that the interests of Rio Tinto , which is a joint-venture partner with Freeport in Grasberg, still needed to be factored into government plans to acquire a 41.64 percent stake in Freeport Indonesia, which would add to the 9.36 percent it already holds.
"This needs to be discussed again, whether (Rio's interest) is converted into shares first, whether Inalum will acquire it first, or what," he said. It is not yet clear whether the government plans impose on Rio the same majority divestment requirement it imposed on Freeport.
State-owned aluminium producer PT Inalum has been appointed by the government to acquire the Freeport stake, and plans to form a holding company under Inalum for that purpose are expected to be carried out this week or early next, Inalum Finance Director Oggy A. Kosasih said during a press conference with Sampurno outlining the formation of the holding company.
The company would group together other state-owned mining units including PT Bukit Asam Tbk, PT Timah Tbk and PT Aneka Tambang Tbk (Antam).
Under a joint venture formed in 1996, Rio has a 40 percent interest in PT-FI's Grasberg contract, which entitles them to a 40 percent share of all production after 2022. Rio has held talks with Indonesia about a possible exit to the venture.
A spokesman for Freeport Indonesia could not be reached for comment on Friday. A Melbourne-based spokesmen for Rio Tinto declined to comment on the matter.
While the plans for Indonesia's purchase remains unclear, Freeport and the government appear to be closer to reaching an understanding on a valuation method for Grasberg. Indonesia had earlier maintained that the stake should not include the value of unmined reserves while Freeport has said "fair market value" should include the reserves.
On an Oct. 25 call discussing Freeport's earnings, Chief Executive Officer Richard Adkerson said the Indonesian government had indicated that fair market value is the right standard "and now we've got to negotiate what that fair market value is."
Meanwhile, the security situation at Grasberg remains tense amid several recent shootings. In the latest incident on Friday, a group of six unknown assailants shot at three police officers driving in a vehicle near the mine, though none of them were injured, the local police said. (Reporting by Fergus Jensen and Wilda Asmarini; Additional reporting by Sam Wanda in TIMIKA; Editing by Christian Schmollinger and Richard Pullin)