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NEW YORK (CBSDFW.COM/AP) — Chipotle, which is still hurting from food safety scares last year, is adding four new people to its board as the burrito chain tries to turn its business around. The picks were made in agreement with activist investor Bill Ackman, whose firm Pershing Square is Chipotle’s biggest shareholder.

Chipotle Mexican Grill Inc. shares rose 2.5 percent to $392.23 Friday morning.

One of the new board members, Ali Namvar, is a Pershing partner. Matthew Paull, a former chief financial officer at burger chain McDonald’s Corp., is on Pershing’s advisory board. The other new members are Paul Cappuccio, a Time Warner executive, and Robin Hickenlooper, a Liberty Global executive.

The board shakeup comes on the same week Chipotle announced that founder Steve Ells would take over as sole CEO.

Sales at the restaurant chain as the company has struggled to win back customers after an E. coli scare last year.

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