Aug 31 (Reuters) - EXFO Inc EXF.TO
* EXFO acquires 33.1% stake in Astellia and announces plans to soon launch a voluntary takeover bid of the company
* EXFO signed an representing an equity stake of 25.4%, at a price of EUR 10 per Astellia share
* Astellia's board of directors has expressed its support for this transaction
* Price of EUR 10 per share proposed by EXFO represents a premium of 44.7% over Astellia's closing share price on August 30, 2017
* Co signed an agreement with Isatis Capital to acquire at same price a majority of its shares, representing an equity stake of 7.7%
* Transaction values the entirety of Astellia's equity (on a fully diluted basis) at approximately 25.9 million euros
* EXFO will initiate an all-cash voluntary public tender offer to acquire Astellia's remaining shares