Matthew Andresen, president and chief executive of Island ECN, has unexpectantly resigned from the electronic communications network following its recently completed merger with Instinet.

Andresen has joined Sanford C Bernstein as head of global trading. The news came on a day when Island parent Reuters was due to receive a $207m (€209) special dividend payment from Instinet to close out the merger between the two rival electronic share dealing networks that specialize in Nasdaq-listed securities. Reuters still holds 62% of Instinet's share capital on a fully diluted basis.