Eladian Partners, a US high-frequency trading firm launched last year by two former Citigroup directors, is considering taking a stake in a Dutch market-making firm as part of its expansion into Europe, according to two sources.

Eladian, which was set up last year by Steve Swanson, a former co-head of global electronic trading at Citi, and his business partner Peter Kent, has held talks with the Amsterdam-based Flow Traders regarding a deal, the sources said.