Middle East businesses are watching tensions between Saudi Arabia and the United Arab Emirates with increasing nervousness, concerned they could impact commerce at a time when both nations are emerging as powerhouses of regional trade and finance.

Those tensions erupted into the open in December when the kingdom gave UAE forces 24 hours to withdraw from Yemen, and Saudi media has since ramped up rhetoric against its eastern neighbor.

While no formal diplomatic or commercial measures have been taken, some companies operating in both countries have begun contingency planning to ensure business continuity should the situation escalate further, according to people familiar with the matter, who requested anonymity in order to discuss private deliberations.