Confirmation expected later today
It's understood Manx Gas has parted company with its managing director.
Tony Nicholls has been in post since 2010 and overseen a number of changes, including a scheme to extend natural gas beyond Douglas and a voluntary regulation of company profits.
Although the company has yet to confirm his departure, a statement is expected to be issued later today (Monday).
The news comes on the day a further protest about the Manx Gas standing charge regime is planned outside its Murdoch House headquarters in Douglas.
That is scheduled for 1pm.