A sign marks the location of the Groupon headquarters in Chicago, Illinois. The online bargain hunter has announced the appointment of former Google executive Margo Georgiadis, saying she would oversee global sales, marketing and operations.

Online bargain hunter Groupon announced the appointment of former Google executive Margo Georgiadis on Thursday, saying she would oversee global sales, marketing and operations.

"Margo is a strong leader with a passion for helping small business owners and consumers," CEO Andrew Mason said in a statement. "We’re thrilled to have her on our team."

Georgiadis was previously Google's vice president in charge of global sales.

In January Google said it was building an online shopping service that would compete with start-up Groupon, which emails members daily deals from local businesses and secures discounts with collective buying power.

The Chicago-based start-up, which offers subscribers online coupons for discounts on a broad range of consumer goods and services, had earlier rejected a reported $5 billion takeover offer from .

Groupon disclosed early in January that its number of subscribers had grown to 50 million from just two million at the beginning of 2010.