The chief executive of the New York Mercantile Exchange has said the exchange is weighing up options in its strategy going forward, while its domestic rivals forge ahead with mergers and consolidation.

James Newsome said Nymex has not decided how to use the estimated $820m (€634m) it has raised since its flotation on November 17, before announcing the exchange is launching an energy index futures contract, its latest challenge to the Intercontinental Exchange.