A select club of London and Manhattan firms have secured coveted roles on a string of big-ticket China floats, it has emerged, as research shows that initial public offerings (IPOs) from the emerging Asian giant are surging in value.

Allen & Overy (A&O) has scooped the key underwriter role on the upcoming float of Bank of China (BOC) alongside Shearman & Sterling, in what has been billed as the world’s largest IPO for six years.