Sienna Investment Managers, the alternative investment and real assets arm of Groupe Bruxelles Lambert (GBL), has acquired pan-European real estate investment manager L’Etoile Properties, more than tripling the value of its assets under management.

Sienna, which was launched by Belgian holding company GBL in 2013, said the acquisition of the €7bn L’Etoile would take its assets under management to €10bn.

Last year, Pedro-Antonio Arias, the former head of real and alternative assets at Amundi, joined Sienna as CEO as the company ahead of a planned move into third-party fund management.

L’Etoile, which has 85 employees in Amsterdam, Hamburg, Paris, Madrid, London and South Korea, has been managing European real estate investments on behalf of international institutional investors for more than 30 years, with a focus on offices, hotels and logistics.

Sienna said it invests across a range of alternative asset classes via external managers and through direct investments and co-investments in private companies.

Coinciding with the acquisition of L’Etoile, Sienna has launched its third-party capital management company and received Alternative Investment Fund Manager approval from Luxembourg regulator, the CSSF.

“Alternative asset management has experienced consistent and sustained growth for many years,” said Arias. “Only global alternative platforms, active in private markets and real assets, will be able to cope with the consolidation to come.

“Thanks to the quality of our shareholder GBL and the acquisition of highly-experienced and successful investment managers like L’Etoile, we are well positioned to capitalise on the consolidation opportunity and play a vital role as an integrator in this sector.”

Didier Unglik, CEO of L’Etoile, said: “This partnership brings an opportunity to accelerate our development in investment products, geographic locations and skills, while keeping our identity.

“We are confident that, with the support of Pedro, the Sienna team and GBL, we will be able to continue our ambitious investment plans and raise and successfully invest further capital for our future funds.”