* Rosneft sees Vankor output at 23 mln t in 2016-document
* Had planned peak production of 25 mln t this year-document
* Field is a key resource for exports to Asia
* Rosneft says to honour supply commitments
By Katya Golubkova
MOSCOW, Oct 23 (Reuters) - Russia's Rosneft, the world's largest listed oil company by output, is cutting its forecast of production at the Vankor field in East Siberia that serves as its main resource base for supplying Asian markets.
Output at Vankor, which feeds in to the Eastern Siberia - Pacific Ocean (ESPO) pipeline, will only reach 23 million tonnes (462,000 barrels per day) in 2016, according to a document obtained by Reuters.
Vankor will pump 21.3 million tonnes this year (428,000 bpd) - below a peak initially seen at 25 million tonnes, according to a provisional forecast on the Krasnoyarsk regional government's website to which public access has been blocked.
An official emailed a copy to Reuters.
Vankor has proven oil reserves of 1.4 billion barrels and is the biggest Russian oilfield to enter production in 25 years. It is vital for the state oil major to meet its growing commitments to supply Asian markets, above all China.
On Tuesday, Rosneft signed an outline deal in Beijing to supply 200,000 bpd to Sinopec for 10 years, bringing CEO Igor Sechin closer to his goal of eventually supplying more than 1 million bpd of oil to China.
Rosneft declined to comment on Vankor's future production, but said it would meet all its supply commitments without having to divert westbound oil flows to cover the new Chinese volumes.
"Rosneft's production plans will without doubt ensure that all oil supply commitments are met," the company said in comments emailed to Reuters.
"In the event of possible deviations, existing agreements and the most profitable supply routes will be prioritised." (Editing by Douglas Busvine and James Jukwey)