Online postage retailer

Stamps.com

(STMP) - Get Report

said John Payne stepped down today as chairman and chief executive.

The company didn't announce a successor and is examining candidates for its vacant CEO and chief financial officer positions, as well as exploring strategic alternatives. Former U.S. Postmaster General Marvin Runyon will get the temporary nod until the position is officially filled.

Earlier this week, Stamps.com said Chief Financial Officer John LaValle and Comptroller Candelario Andalon were leaving the company to pursue other interests.