DUBAI: Saudi Arabia's bourse fell further on Tuesday in line with oil prices, while most other Gulf markets rose, reversing a pattern seen in the last few weeks when the Kingdom outperformed the region.

Brent and US oil dropped about 2 percent each as Iran and six world powers ramped up the pace of negotiations in an effort to reach a preliminary deal on Tehran's nuclear program by the end of the day. If achieved, a deal could ease sanctions and allow more Iranian crude onto world markets.

The Tadawul All-Share Index (TASI) lost 2.0 percent to 8,779 points as heavyweight Saudi Basic Industries Co., the Kingdom's top petrochemicals producer, dropped 3.2 percent and was the main drag.

Al-Rajhi Bank, the leading retail lender whose earnings have been affected by a regulatory cap on consumer finance fees introduced last year, dropped 2.6 percent as a wider banking sell-off continued.