Chief executive Nan Williams said in a statement: ‘We have had to take this action to protect our business and staff. Loyalty, trust and commitment are bywords for the way Four does business. And we will always take action to protect our clients, our staff and our business when people betray those high standards and the trust we expect.
‘At this point, we are not able to share any further details as we are considering our right to take further legal action.’
The termination of Burns’ employment is believed to be effective from today.
Burns could not immediately be reached for comment.
He joined Four Communications as MD of corporate PR, issues and crisis management in late 2011, having previously worked as a senior consultant at Bell Pottinger Sans Frontieres.
Burns previously served as the Abu Dhabi-based vice-president of corporate comms of Etihad Airways and was head of corporate comms at British Airways for five years, before resigning in 2006 after a price-fixing case brought by the Office of Fair Trading.
The price fixing-related trial against Burns and three other former British Airways colleagues subsequently collapsed in 2010.