NEW YORK (

TheStreet

) --

Groupon

(GRPN) - Get Report

shares plunged on Monday as two members of its board, including

Starbucks

(SBUX) - Get Report

CEO Howard Schultz, resigned.

Schultz is stepping down immediately, while venture capital firm Accel Partners' Kevin Efrusy's resignation from the board of directors will be effective as of the company's annual meeting in June. Groupon stated in a

press release

that Daniel Henry, the chief financial officer of

American Express

(AXP) - Get Report

had joined the board and Robert Bass, a vice chairman of

Deloitte LLP

should join its board after a shareholder vote at the annual meeting.

"With their deep financial, accounting and operational experience, Dan and Bob will provide invaluable expertise to the Board going forward," said Eric Lefkofsky, Groupon Chairman.

Groupon has been besmirched by accounting issues since its IPO, when it used a controversial method of accounting to inflate its revenue drastically. It recently

restated fourth-quarter earnings

, citing a shift in the company's fourth-quarter deal mix and higher price offers, which have higher refund rates.

Groupon could not immediately be reached for comment.

Shares traded down sharply on Monday, down 10.56% to finish at $10.71.

Interested in more on Groupon? See TheStreet Ratings' report card for

this stock

.

Check out our new tech blog,

Tech Trends

. Follow TheStreet Tech

on your wireless devices

.

--

Written by Chris Ciaccia in New York

>To follow the writer on Twitter, go to

http://twitter.com/commodity_bull

.

>To submit a news tip, send an email to:

tips@thestreet.com