By Inti Landauro

PARIS--The French stock market regulator Wednesday said it will investigate an internet hoax that pushed shares of construction firm Vinci SA (DG.FR) into a flash crash on Tuesday afternoon.

L'Autorite des Marches Financiers as the regulator is known said it will determine who was responsible for the hoax that caused a "serious market malfunction."

"This is spreading of false information" that requires the AMF to investigate, it said. The regulator will consult with all parties involved and will seek to discover who profited from what was a possible price manipulation.Vinci shares fell almost 18% in mid-afternoon trading after several financial media outlets picked up a forged statement they received that said the company had fired its chief financial officer following accounting irregularities worth several billion euros. Prices started to recover later in the afternoon when Vinci filed a denial to the stock-market regulator.

Attempts to manipulate company share prices are common, though generally they aren't so sophisticated or successful.

Write to Inti Landauro at inti.landauro@wsj.com

(END) Dow Jones Newswires

November 23, 2016 10:05 ET (15:05 GMT)

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