In Abu Dhabi, the index dropped 0.7%, retreating further from record highs, weighed down by a 1.3% fall in the country's largest lender First Abu Dhabi Bank
Dubai's main share index fell 0.7%, weighed down by a 1.1% drop in Emirates NBD Bank and a 1% decline in sharia-compliant lender Dubai Islamic Bank.
"The Saudi announcement will likely negatively affect companies in the Emirates in the short-term," said Daniel Takieddine, market analyst at FXPrimus.
Meanwhile, Brent crude futures surged above $70 a barrel on Monday for the first time since the COVID-19 pandemic began, while US crude touched its highest in more than two years.
Brent oil climbed to a 13-month high of $67.30, after US government data on Wednesday showed a drop in crude output as a deep freeze in Texas disrupted production last week.
Saudi Arabia's benchmark share index rose 0.9%, with Al Rajhi Bank rising 2% and Saudi Telecom Company climbing 3.3%.
Saudi Arabia's benchmark index fell 0.2%, hit by a 0.7% fall in Al Rajhi Bank and a 0.8% decline in the country's largest lender National Commercial Bank.
The Saudi economy is forecast to shrink by 5% this year, according to the International Monetary Fund.