Struggling Russian automotive group AvtoVAZ (AVAZ.RS) plans to collaborate on purchasing with core shareholder Renault SA (RNO.FR) and Japan's Nissan Motor Co. (7201.FR) in a bid to reduce costs, a Renault spokesman said Friday.

An agreement could be reached as early as next week, said the spokesman, who declined to provide further details.

Renault and Nissan have pooled their purchasing for years as part of the Renault-Nissan alliance that is cemented with cross-shareholdings. Renault owns 44.3% of Nissan while Nissan has a 15% interest in Renault.

A joint venture between Renault and Nissan, Renault Nissan Purchasing Organisation (RNPO), is responsible for all purchases by the two automakers. RNPO made purchases totalling EUR60 billion in 2008, achieving significant savings for the two partners.

Both brands maintain their own purchasing departments to cover the needs specific to each partner.

Renault in the first quarter of 2008 paid $1 billion for a 25% shareholding in AvtoVAZ, Russia's leading vehicle manufacturer and owner of the Lada brand.

The stated goal of that long-term alliance is to accelerate the transformation of AvtoVAZ into a global automotive player, with a production capacity of more than one million vehicles a year. The plan is to leverage Renault's technology to improve, renew and expand the Lada range of vehicles.

Due to collapsing sales in the Russian market, however, AvtoVAZ contributed a loss of EUR182 million to Renault's first-half earnings. The value of Renault's share in the net assets of AvtoVAZ dropped to EUR295 million at the end of March from EUR550 million six months earlier.

Renault makes its low-budget Logan cars at a plant outside Moscow and is doubling the capacity of the plant to 160,000 vehicles a year.

At 0930 GMT, Renault's shares traded down 1.6% at EUR33.16 in a broadly lower Paris market.

-By David Pearson, Dow Jones Newswires; +331 4017 1740, david.pearson@dowjones.com