INTERVIEW-UPDATE 1-Venezuela delays Japan aluminium stake buy

* Purchase of 20 percent state delayed, valuation ready * Venalum losing about $1,000 per tonne of aluminum * Forecasts price of $1,800 tonne for end 2009 (Adds details and comment from Venalum) By Fabian Andres Cambero CIUDAD BOLIVAR, Venezuela, Sept 7 (Reuters) - Venezuela has delayed the purchase of a 20 percent share that six Japanese companies own in aluminum smelter Venalum until the economy picks up, the head of Venalum said in an interview. The six companies, including Showa Denko <4004.T> and Marubeni <8002.T>, said in June they wanted to sell their stake in Venalum after a dispute about prices for the metal. The government already owns 80 percent and had been due to buy the remaining share last month. Venalum's president Carlos Acosta told Reuters the valuation of the Japanese companies' stake was ready and was adjusted for factors such as inflation. "All that remains is to wait for the right moment and the economic conditions," Acosta said on Sunday, without predicting a date or revealing the government's estimate of the value of the Japanese share. Media reports have estimated that 20 percent of the company is worth $510 million. Acosta said funds for the purchase of the buyout could be drawn from a loan of between $2 billion and $3 billion that Venezuela is seeking in private markets to help its struggling basic industries sector. Acosta said Venalum's production costs are about $2,500 per tonne, and that the average aluminum price for the first half of the year was $1,490 per tonne. He forecast aluminum prices would rise at the end of this year to an average of $1,800 per tonne and continue higher next year. The company expects to produce 436,000 tonnes of the metal this year. Kobe Steel <5406.T>, Sumitomo Chemical <4005.T>, Mitsubishi Materials <5711.T> and Mitsubishi Aluminum are also involved in Venalum. (Writing by Frank Jack Daniel; editing by Jeffrey Benkoe)