Russia's top crude oil producer Rosneft said on Tuesday its board had approved deals to sell oil product cargoes to BP worth over $6 billion, on top of a previous deal to sell oil worth $5.3 billion.

The Russian state-owned company said in a filing that it would sell up to 3.2 million metric tons of fuel oil to BP Singapore worth as much as $2.6 billion from the Far East ports of Nakhodka or Vanino between November 2013 and December 2014 with a possibility to lift it in 2015.

Rosneft has not disclosed the time frame for other deals, but a source familiar with the agreements said the deliveries should be fulfilled over the next 12 or 13 months.

Rosneft declined to comment further.

Last month, BP signed deals to buy $5.3 billion of oil from Rosneft.

Rosneft will also sell up to 1.44 million metric tons of diesel to BP worth as much as $1.77 billion from the Black Sea port of Tuapse.

It will sell up to 2 million metric tons of fuel oil to BP worth as much as $1.62 billion from the Baltic port of Ust-Luga and up to 60,000 metric tons of naphtha worth $65 million from Tuapse.

BP raised its stake in Rosneft to nearly 20 percent as part of the Russian oil major's $55 billion takeover of TNK-BP which was completed in March.

BP is now Rosneft's largest shareholder after the government and is exploring the possibility of joining Russian onshore energy projects after being shut out of any Arctic deals.

The government currently owns a 69.5 percent stake in Rosneft.

Russia's First Deputy Prime Minister Igor Shuvalov suggested that this time Britain's BP is given a head start in any Rosneft privatization talks, while announcing Tuesday that the government may not cede control of oil giant Rosneft until 2016.

The recommendation to push back Rosneft's sell-off by at least a year came from "experts" who advise the cabinet on its current three-year $50 ­billion privatization drive, said Shuvalov, adding Rosneft's sale "negotiations will be conducted with existing shareholders, including BP."