Saudi Arabia's benchmark index .TASI fell 0.7% for a second consecutive session, with most constituents ending in negative territory.
Saudi Arabian Mining 1211.SE declined 3.3%, while Saudi National Bank 1180.SE, the kingdom's largest lender by assets, lost 1.2%.
"The Saudi market could remain vulnerable to further downside if investors continue taking profits after several sessions of gains," said Hani Abuagla, senior market analyst at XTB MENA.
Qatar's benchmark index .QSI edged 0.1% lower, weighed down by declines in financial and communications shares.
Doha Bank DOBK.QA dropped 5.1%, while The Commercial Bank COMB.QA fell 2.5%. In contrast, QatarEnergy-linked Industries Qatar IQCD.QA gained 0.6%, and Gulf International Services GISS.QA rose 3.9%.
QatarEnergy sold at least 7 million barrels of various Qatari crude grades through a tender this week for October loading, several trade sources said on Friday.
"Looking ahead, GCC markets are likely to remain sensitive to shipping developments in the Strait of Hormuz and any diplomatic progress," Abuagla said. "Strong domestic fundamentals may help limit downside risks, though investor caution could persist as global bond yields rose following Warsh's remarks, with attention now turning to the Fed's next meeting."
Gulf markets fall as Fed rate-hike expectations rise
Most Gulf stock markets closed lower on Sunday as investors turned cautious after U.S. Federal Reserve Chair Kevin Warsh reiterated the central bank's commitment to bringing inflation back to target, boosting expectations of another interest-rate increase.
Warsh said at the Fed's annual economic symposium in Jackson Hole that policymakers would "have work to do" if they were not confident that underlying inflation was returning to the central bank's 2% target. He also noted that financial conditions did not appear restrictive.
Following his remarks, market-implied odds of a rate increase at the Fed's September meeting rose to 55.7% from 35.4% on Thursday, according to CME Group's FedWatch tool.
Gulf markets are particularly sensitive to changes in U.S. monetary-policy expectations since most regional currencies are pegged to the dollar.
Egypt's blue-chip index slips; Abu Qir Fertilizers rises
Outside the Gulf, Egypt's blue-chip index .EGX30 slipped 0.3%, with most shares trading lower. Commercial International Bank COMI.CA fell 0.8%, while Talaat Moustafa Group TMGH.CA lost 1.3%.
Abu Qir Fertilizers and Chemical Industries ABUK.CA, however, rose 4.8% after the company said it had expanded ammonia production capacity and reduced natural-gas consumption.