Dec 15 (Reuters) - Exfo Inc EXF.TO :
* EXFO , WHICH HOLDS 33.1% OF ASTELLIA'S EQUITY, ANNOUNCES THE OPENING OF ITS PUBLIC CASH TENDER OFFER FOR ASTELLIA'S REMAINING EQUITY
* EXFO INC - OFFER IS PROPOSED AT A PRICE OF 10 EUROS PER ASTELLIA SHARE
* EXFO - OFFER TO BUY OUTSTANDING ASTELLIA SHARES NOT ALREADY OWNED BY EXFO TO BE OPENED THROUGH JAN. 23, 2018