July 31 (Reuters) -

UnitedHealth ( UNH ) said on Thursday it will replace its

finance chief John Rex with an external hire, Wayne DeVeydt,

adding to the management changes at the health insurer that has

been struggling to control its medical costs.

Rex, who has been handling the role since 2016, will

continue as a strategic advisor to the CEO, with the changes

effective September 2.

DeVeydt was most recently managing director and

operating partner at Bain Capital, and was also the finance

chief of UnitedHealth's ( UNH ) rival Elevance, then called

Anthem, between 2007 and 2016.

The largest U.S. health insurer had seen an abrupt

departure of Andrew Witty as CEO in May, with Stephen Hemsley

replacing him following struggles with elevated medical costs

that were also seen in the rest of the industry.

Hemsley is under pressure to regain investor trust as the

company faces financial struggles and reputational damage that

surfaced after the then-CEO of its health insurance unit was

gunned down on a New York City street in December.