Significant changes at top management level in Bus Éireann have taken place in recent days with chief executive Martin Nolan announcing his departure earlier this week.
Just before Christmas, the long-standing director of human resources at the company Joe Kenny also left.
Bus Éireann announced on Monday that its chief financial officer Ray Hernan will take over as acting chief executive officer.
Mr Hernan was a former director of finance at Ryanair and also held senior financial roles at Brown Thomas and Arnotts.
Mr Nolan said on Monday that given his term of office – which had been extended – was due to expire, now was the right time to ensure a new team was put in place to manage the next phase of change and development at the company.
He has been chief executive of Bus Éireann for the last six years. He joined the State-owned transport company in 1997 and has also worked as chief operating officer and chief financial officer.
Mr Hernan said: “I am delighted to assume my new role as we prepare to implement a strategy that is focused on maintaining the momentum of growth of recent years, but also addressing the financial challenges and efficiency needs of this business which is urgently required in a much more competitive marketplace.”
Bus Éireann chairman Aidan Murphy said earlier this week plans were being finalised to address serious financial issues at the company "and we are ready to implement, as a matter of urgency, the structural changes and efficiency initiatives which are required to position the business for future growth and viability".