On Thursday, Moody's changed the outlook for the two companies to negative from stable, citing the impact of the COVID-19 pandemic.
The Dubai real estate sector has for years struggled with oversupply and sluggish economic growth.
However, the index's fall was cushioned by a 2.6% leap in Islamic Arab Insurance (Salama) following an increase in foreign ownership limit to 49% from 25% earlier.
Expo 2020 Dubai is now set to take place from October 1, 2021 to March 31, 2022, roughly a year later than initially planned.
The Abu Dhabi index retreated 1.7%, driven down by a 2.3% fall in the country's largest lender First Abu Dhabi Bank and a 3.7% slide in Abu Dhabi Commercial Bank.
Saudi Arabia's benchmark index reversed earlier losses to close 0.2% up. Oil giant Saudi Aramco gained 1.7% despite Credit Suisse slashing price target to 26.7 riyals from 28 riyals, while Yanbu National Petrochemicals advanced 5.4%.
Saudi Basic Industries (SABIC), the world's fourth-biggest petrochemicals company, reported a net loss in the first quarter, which it blamed on impairment losses on assets and lower demand for its products in the wake of the COVID-19 pandemic. However, the stock ended flat.
In Qatar, the index slipped 0.2%, hurt by a 1.4% fall in petrochemical firm Industries Qatar.
Egypt's blue-chip index lost 1.2%, as Commercial International Bank dropped 1%, while Qalaa Holding declined 4.4% after posting a fourth-quarter loss.