AMSTERDAM, Sept 24 (Reuters) - Shares in Majorel Group , a Luxembourg-based operator of call centres, fell on their first day of trading on the Euronext stock exchange in Amsterdam, after a listing that valued the company at 3.3 billion euros ($3.9 billion).

Its co-owners, German publisher Bertelsmann and Moroccan partner Saham, sold 20% of its shares to institutional investors in the offering at 33 euros, near the bottom of a 32-39 euro range proposed last week, raising around 660 million euros. The shares were down 6.1% at 31 euros as of 0846 GMT. Majorel, headquartered in Luxembourg, employs 60,000 people in 31 countries. It reported a first-half core profit of 154 million euros on revenue of 842 million.

The placement was managed by JP Morgan, BNP Paribas and Citi.

($1 = 0.8501 euros) (Reporting by Toby Sterling; editing by Jason Neely)