* Oman says cuts to meet landmark producers' agreement
* June timing still subject to change - source
* Fall in Omani crude exports likely to affect China imports (Adds comments, details)
By Florence Tan
SINGAPORE, March 24 (Reuters) - Non-OPEC oil producer Oman has notified customers in Asia that it could reduce supplies of crude by 15 percent from June to meet demand at a domestic refinery, and as part of its commitment to cut output under a landmark producers' agreement, three people who received the notices said on Friday.
A cut would likely affect China most, as the world's second-largest oil consumer buys close to 90 percent of Oman's exports.
Oman's Ministry of Oil and Gas (MoG) told buyers that the supply cuts are also to meet rising domestic demand at the state-owned Sohar refinery, which is being expanded, the people said. They declined to be identified because they weren't authorised to discuss the matter publicly.
"Oman is giving buyers advanced notice of a potential cut in exports in June," one of the people said, adding that customers were informed the timing could still change. The cut won't necessary lead to problems for Chinese buyers as there are many other supplier choices in the well-supplied Asia crude market, he said.
MoG could not be reached for comment as its office is closed for weekend.
Oman's Minister of Oil and Gas Mohammad bin Hamad al-Rumhy said in October last year that the country's exports would drop by about 50,000 barrels a day when new refining capacity comes on stream in early 2017.
The country cut its crude output by 45,000 barrels per day in January to 965,000 bpd from the previous month, to comply with a deal struck late last year by the Organization of the Petroleum Exporting Countries and non-OPEC producers to support oil prices. (Reporting by Florence Tan; Editing by Christian Schmollinger and Kenneth Maxwell)