The asset management arm of Switzerland's Pictet has strengthened its thematic investment expertise with three new additions.

Pictet Asset Management has hired Simon Gottelier, Peter Lingen and Christian Roessing as senior investment managers within its thematic equities team.

Gottelier will cover the firm's water strategy, which had $4.11 billion in assets under management as of the end of last year. He joins from Impax Asset Management in New York, where he managed the Impax Global Water strategy. He also co-managed Impax's All-Cap Resource Optimisation Leaders strategy.

Alongside Karen Kharmandarian, Lingen will co-manage the $315 million robotics strategy, which Pictet launched in October last year to allow clients to invest in robotics and artificial intelligence technologies.

Roessing will work on the firm's clean energy strategy, which had $1.04 billion in assets under management as of the end of 2015. He previously spent seven years at Vontobel Asset Management, where he was most recently deputy portfolio manager for the Vontobel Fund – Clean Technology.

In their newly-created roles, Gottelier, Lingen and Roessing will be based in Geneva.