A chief executive has been appointed to the merged trust proposed by Royal West Sussex and Worthing and Southlands Hospitals trusts.
Marianne Griffiths, currently interim chief executive of Royal West Sussex, has been given the role "in principle" while it waits for approval for the merger from health secretary Alan Johnson.
In a joint statement, Royal West Sussex chair Susan Pyper and Worthing and Southlands Hospitals chair Tom Robson said: "This is an excellent step forward for the new organisation as we work towards a merger in April.
"Marianne has a wealth of experience working in the regional NHS and she will bring her energy and enthusiasm to help shape the new trust for patients and staff."
Ms Griffiths was previously deputy chief executive and director of commissioning and delivery at NHS South East Coast.