Russian Prime Minister Vladimir Putin left China Wednesday after a visit that yielded $7 billion in trade pacts but no breakthrough on a long-delayed gas deal with the world's top energy consumer.

Putin held talks with his Chinese counterpart Wen Jiabao and President Hu Jintao in Beijing on his first foreign trip since he announced plans to reclaim the Russian presidency.

Russia is the world's largest producer of energy, and Putin said progress had been made on a 30-year deal to pump gas to China that was signed in 2009 but has been mired in disagreements over pricing.

"We are close to the final stage of work on gas supplies to the Chinese market," Putin told journalists Tuesday of the agreement.

Russian Deputy Prime Minister Igor Sechin said Wednesday the two countries were "standing on the threshold of gas delivery agreements," Russia's Interfax news agency reported.

"We are conducting normal, routine work that will end with the signature of a contract -- of that I am certain," Interfax quoted Sechin, who is responsible for the Russian energy sector, as saying.

The agreement could eventually see almost 70 billion cubic metres of Russian gas sent to China annually over the 30-year period.

A spokesman for China's foreign ministry also said negotiations on the deal, between Russian gas giant Gazprom and China National Petroleum Corporation, would continue.

China and Russia are both veto-wielding permanent members of the UN Security Council, and last week infuriated the West by blocking a UN resolution against Syrian President Bashar al-Assad's deadly crackdown on protests.

Russian Foreign Minister Sergei Lavrov said this week Moscow and Beijing were ready to propose a new UN resolution on Syria that would condemn violence carried out both by Assad's regime and the rebel opposition.

No mention of the resolution was made during the visit, but China on Wednesday broke with its longstanding policy of non-interference in Syria to press for prompt reforms.

China became Russia's top trading partner for the first time last year and the two countries want to increase trade from $70 billion this year to $100 billion by 2015 and $200 billion by 2020.

China's sovereign wealth fund signed a deal during Putin's visit to invest in a new Russian state-backed fund, to encourage foreign direct investment in Russia.

The China Investment Corporation will put $1.0 billion into the Russian Direct Investment Fund, founded in June with backing from Putin and Russian President Dmitry Medvedev.

The two countries also agreed on a price for Russian oil exported to China through a cross-border pipeline that started operating at the beginning of the year, the official China Daily newspaper said.

Russia had accused China of underpaying it by tens of millions of dollars due to a tariff dispute, but Putin said the two sides had "agreed on crude oil prices", the report said.

Putin told Hu that Russia wanted to boost cooperation with China in "energy technology, aviation and space exploration", China's official Xinhua news agency reported.

Putin has paid frequent visits to China in his capacity as president and prime minister since he took power in 1999.

His latest two-day trip to Beijing follows last month's announcement that he plans to reclaim the presidency in a bid that may keep him in power until 2024.

Putin is well known in China, where businessmen and politicians consider him the top figure in the Russian political pecking order. On Wednesday, Hu called him "an old friend of China."