Dubai's stock market suffered its biggest one-day fall since last December on Sunday as bourses across the Gulf tumbled, hit by further weakness in oil prices and the decision by Fitch Ratings to cut its outlook for Saudi Arabia's debt.

The main Dubai index sank 7.0 percent to 3,451 points, its lowest close since March 30. Top real estate developer Emaar Properties plunged 8.3 percent while builder Arabtec dropped its 10 percent daily limit.

Abu Dhabi's index fell 5.0 percent and Qatar was down 5.3 percent in late trade.