The U.S. company that Avanquest seeks to buy has total annual revenues of about $180 million (123 million pounds), the source added, refusing to name the target.

Avanquest Chief Executive Officer Pierre Cesarini declined to comment.

The French group was founded in 1984 and has been listed since 1996. It reported total revenues of 108.9 million euros for the 2014-2015 fiscal year and an operating profit of 1.2 million euros.

(Reporting by Matthieu Protard; Writing by Mathieu Rosemain; Editing by Andrew Callus and Keith Weir)