UPDATE 2-Saudi to deepen May oil supply cuts to 2 Asia buyers

* Saudi deepens cuts to 2 in Asia, vs steady U.S. supplies

* Deeper cuts follow OPEC deal to keep curbs unchanged

TOKYO, April 10 (Reuters) - Saudi Arabia will unexpectedly cut oil supplies to some major Asian refiners next month, suggesting the world's top exporter may be more concerned than some of its OPEC peers about swelling crude inventories.

OPEC agreed last month to keep its supply quotas unchanged for now, stressing the need for compliance with previous curbs that had helped halt a $100 dive in oil prices.

But with crude now rising back above $50 a barrel -- a price some members have signalled would be acceptable for now -- analysts say discipline looks unlikely at the moment, despite world crude stocks still climbing as the deepest recession in decades curtails demand, forcing refiners to cut production.

While the cuts to Asia appeared modest, and were in contrast with news on Thursday of steady Saudi supplies to U.S. customers, they could signal unease about the precarious state of the physical oil market, particularly with a deepening contango signalling a persistent glut of prompt oil.

"Our firm anticipated cuts around this level," one refinery company source said, declining to be identified because the information was confidential.

One major buyer in Asia said it had been notified that Saudi will supply crude at 8 to 9 percent below contracted volumes in May, versus cuts of about 7 percent in April. A second source said his company would see supplies cut by about 11 percent in May, versus estimated cuts of 8 percent for April.

A source at a third refiner said its supplies would be unchanged, while several other refiners said they had yet to be notified by state oil company Saudi Aramco of May shipments.