Orders passed a threshold of 35 percent of the total market value of the 40 blue-chip stocks that make up the index, triggering an automatic halt in the calculation under exchange rules, Frederique Vigezzi told AP.
Calculation of the index was suspended for about 15 minutes as operators of the Euronext Paris exchange worked to confirm the orders. Overall trading in the exchange was not suspended.
When the calculations resumed shortly before 11 a.m. (0900 GMT) on Wednesday, the index recovered some lost ground, and was down 5.5 percent to 3,526.78. It fell along with many other bourses in Asia and elsewhere in Europe.