AN independent investigation has been ordered into a publicly-owned bus firm dogged by a bitter boardroom battle.

Edinburgh City Council made the move after the embarrassing row at Lothian Buses involving four directors which led to a call for answers after the spat was episodically leaked to the media.

Lothian Buses, the sister company of Edinburgh Trams, is to be scrutinised after the row between the chief executive, Ian Craig, who was cleared of any wrongdoing after an earlier investigation, and the company's finance, engineering and operations directors.

Mr Craig, operations director Bill Campbell, engineering director Bill Devlin and finance director Norman Strachan, who each earned between £200,000 and £270,000 in 2013, are all to leave the firm but their handshake packages are being questioned.

The latest move is revealed in a joint statement that includes the signatures of council leader Andrew Burns and deputy Steve Cardownie.

They said: "Lothian Buses is one of Edinburgh's best loved companies, winning numerous awards and boasting hundreds of thousands of loyal customers who rely on its services day in, day out.

"The council recognises that the past few months have been an unsettling time for you with much speculation about the company in the media.

"As majority shareholder in Lothian Buses, the council has been at pains throughout to seek a sustainable solution to the issues, in the best interests of all Lothian Buses staff, passengers and council taxpayers generally."

The statement said that at last week's council meeting, a number of Lothian Buses employees presented a petition to councillors.

It added: "As a result of this meeting, an independent report has now been commissioned by the council to look at the recent events at Lothian Buses, including the council's actions as majority shareholder.

"It is important that all the facts of this matter are set out clearly and conclusively in the independent report so that the company can move on positively with a focus on the future and continue to deliver an excellent service for the city."