Dec 13 (Reuters) - UnitedHealth Group ( UNH ) CEO Andrew

Witty wrote in a New York Times opinion piece on Friday that the

healthcare system was flawed and was a "patchwork built over

decades."

In the NYT article, Witty mourned the killing of Brian

Thompson, the CEO of UnitedHealth's ( UNH ) health insurance unit, last

week. The killing has ignited an outpouring of anger from

Americans struggling to receive and pay for medical care.

(Reporting by Manas Mishra in Bengaluru; Editing by Anil

D'Silva)