UPDATE 1-Dollar Tree taps company insider Michael Witynski as CEO

(Adds details on Witynski, Philbin)

July 20 (Reuters) - Discount retailer Dollar Tree Inc said on Monday insider Michael Witynski has taken over as chief executive officer from Gary Philbin, who will retire after serving in the role for nearly three years.

Witynski, 57, was the enterprise president and led merchandising, store and supply chain operations for both the Dollar Tree and Family Dollar brands.

He has also served as chief operating officer during his 10-year tenure at the company.

Philbin, 63, has been with the dollar store operator for nearly two decades and will stay on as a board member through Sept. 23, the company said.

The development of Dollar Tree’s private label brands and marketing was largely driven by Philbin, with company’s stock gaining about 14.5% since he became the CEO in September 2017. (Reporting by Uday Sampath in Bengaluru; Editing by Shounak Dasgupta and Sriraj Kalluvila)