A $2bn (€1.4bn) oil and gas merger has been announced but global investment banking revenues have taken three months longer than last year to reach the $40bn mark.

Global investment banking fees from mergers and acquisitions, equity, debt and syndicated loan underwriting hit $40.05bn on August 22 compared to last year when revenues reached the same point on June 2, according to Dealogic, the investment banking research provider.