UPDATE 1-Abu Dhabi deepens June crude supply curbs to Asia

SINGAPORE, April 28 - OPEC-member United Arab Emirates (UAE) will deepen curbs on June crude supplies to Asia across its four main grades compared to the reductions in May, the state oil company said on Tuesday.

The cuts to Murban, Lower Zakum and Umm Shaif grades are the deepest since the UAE began cutting production late last year, and comes ahead of the producer group's next meeting on May 28.

Abu Dhabi National Oil Co (ADNOC), the main oil producer for the UAE, would supply Murban crude at 18 percent below contracted volumes in June compared with a 15 percent cut in May, it said in a statement sent by fax.

Abu Dhabi will also cut supplies of Lower Zakum and Umm Shaif by 18, while Upper Zakum supplies will be 16 percent below the contracted volumes in June, deeper than curbs in May.

ADNOC also said it would continue to keep shipping limits on exports in place for June, depriving buyers of the option to load an additional 5 percent above contracted volumes on each cargo, a standard industry practice known as "operational tolerance".

Following are the cuts in ADNOC term crude supplies to Asian lifters since December 2008.

Dec 08 Jan 09 Feb 09 Mar 09 Apr 09 May 09 Jun 09 Murban 15 % 15 % 15 % 10 % 15 % 15 % 18 % Lower Zakum 10 % - % 10 % 10 % 15 % 15 % 18 % Umm Shaif 5 % - % 10 % 10 % 15 % 15 % 18 % Upper Zakum 5 % 3 % 15 % 15 % 17 % 10 % 16 %