Saudi British Bank (SABB) slipped 0.6% as it traded ex-dividend.
In Dubai, the index ended up 1.6%, driven by a 6.3% surge in shopping centres operator Emaar Malls and a 1.2% gain in sharia-compliant lender Dubai Islamic Bank.
But Emirates Integrated Telecommunication (du) dropped 3.2% as it traded ex-dividend.
The Abu Dhabi index gained 1.9%, led by a 2.8% rise in First Abu Dhabi Bank FAB.AD. The United Arab Emirates' largest bank called a board meeting on April 27, where it will approve first-quarter earnings.
Dana Gas leapt 6.5%. The energy firm announced plans to use the proceeds from its Egyptian assets, which has been trying to sell, to pay down its sukuk, an Islamic bond which is due in October.
The Qatari index gave up early gains to close 0.3% lower. Masraf Al Rayan fell 2.6% before its first-quarter earnings announcement.
However, the index's fall was cushioned by a 6.8% surge in Qatar Gas Transport Company (Nakilat).
The energy shipping and transport company on Monday posted net profit of 279.2 million riyals ($76.70 million) for the first quarter of 2020, up from 235.9 million riyals in the same quarter a year ago.
Among other stocks, Doha Bank gained 0.7% and Vodafone Qatar climbed 4.5% after the duo reported higher quarterly net profits.
Outside the Gulf, Egypt's blue-chip index rose 3.3%, with all stocks on the index gaining. Commercial International Bank was up 3.8%.
Stock exchange data showed that Egyptian and Arab investors were net buyers of the stocks.