TheStreet

Shares of Criteo S.A.  (CRTO - Get Report) tumbled nearly 19% to $17.82 Tuesday after analysts at KeyBanc Capital Markets and SunTrust Robinson Humphrey cut their ratings on the tech company's stock on news that Alphabet Inc.'s (GOOG - Get Report) Google is considering implementing new restrictions on how it handles third-party advertisements.

KeyBanc's Andy Hargreaves lowered his rating on the stock to sector weight from overweight, writing that "restriction to third-party tracking in Chrome could cause massive disruption to Criteo and the digital ad industry." 

SunTrust's Matthew Thornton downgraded the stock to hold from buy and cut his price target to $24 from $32, citing "uncertainty" around Google's plans. He estimated that Chrome may account for half of Criteo's revenue.

The analysts were reacting to an AdWeek story that said Google is considering changes to its handling of third-party ads in Chrome and its Google Marketing Platform.

The Paris-based company provides an advertising platform for the open Internet in France and internationally.

How Much Money Will I Need to Retire?

Want to learn about retirement planning from some of the nation's top experts? Join TheStreet's Robert "Mr. Retirement" Powell live in New York on April 6 for our Retirement Strategies Symposium. For a limited time, tickets are available for $99 for this full-day event. Check out the agenda, learn about the speakers and sign up here.