Yes there are quite few in the UK. Sporting Index would be the best but also Cantor Fitzgerald and IG Index. www.sportingindex.com would be Sporting's site and, I think, www.cantorsport.com would be for cantor. I doubt that Cantor take US citizens though due to their bond trading and broking arms in US. I have no idea whether Sporting would take a US citizen either but you could call them.
