(Repeats to additional subscribers)
* Plan part of Renault-Nissan bid to up stake to 50 percent
* Would buy from Russian Technologies, Troika Dialog
* Russian Tech sees AvtoVAZ worth $2.8-$2.9 bln in 2011
* Nissan says details not yet finalised
(Adds details, background)
MOSCOW, Nov 19 (Reuters) - Japan's Nissan plans to buy 10 percent of Russia's top carmaker AvtoVAZ next year as part of a bid with partner Renault to secure 50 percent, a Russian state firm said on Friday.
A spokeswoman for Renault-Nissan said the sides had yet to reach a final agreement on the stake size, the price and the timing of the deal.
Russian Prime Minister Vladimir Putin this month backed Renault-Nissan's bid to increase its stake in AvtoVAZ, producer of the Lada brand, to 50 percent from 25 percent now.
"Russian Technologies will sell 4 percent, and Troika Dialog will sell 6 percent," Russian Technologies head Sergei Chemezov told reporters. Russian Technologies and brokerage Troika Dialog each own 25 percent of AvtoVAZ.
Chemezov said Russian Technologies estimated that AvtoVAZ is currently worth $2.4 billion, but its value would rise in 2011 when the deal is expected to take place.
"Next year it will already be $2.8-2.9 billion," he said, adding that Russian Technologies wanted to sell the shares in the first or second quarter of 2011. (Reporting by Gleb Stolyarov; Writing by Maria Kiselyova; Editing by Erica Billingham)