SINGAPORE - Middle East crude benchmark DME Oman's differential to Dubai swaps, a gauge for physical market strength, on Tuesday flipped to a discount for the first time in four months.

The Oman differential dropped to a discount of 9 cents a barrel, from a premium of 77 cents a barrel on Monday, Reuters calculations based on market data showed.

(Reporting by Shu Zhang, editing by Louise Heavens) ((shu.zhang@thomsonreuters.com; +65-6870-3549; Reuters Messaging: Twitter @shuzhang4))