LONDON—Three-quarters of British chief executives say they are considering moving their headquarters or some of their operations outside the U.K. as a result of the country’s vote to leave the European Union, according to a survey by accounting firm KPMG.

The firm polled one hundred CEOs at companies involved in businesses such as manufacturing and retail, with annual revenue ranging from £100 million ($129.7 million) to more than £1 billion. Among those polled, 23% said they were “definitely considering” a move as a result of the June 23 vote by Britain to leave the EU. A further 53% said they would “probably” consider a move.

“CEOs are reacting to the prevailing uncertainty with contingency planning,” said Simon Collins, chairman of KMPG U.K., in a statement. “For many CEOs, it is important that they plan different scenarios to hedge against future disruption.”

Many executives at multinationals and big companies in Britain publicly campaigned against Brexit, citing in particular the EU’s freedom of movement for employees and its common market as advantages. Others, many of them executives at smaller firms or small business owners, said they favored Brexit because they thought British business would thrive outside the EU.

Among the executives KPMG polled, 72% said they voted to remain in the EU. A further 25% said they voted to leave.