Ladbrokes, the betting shop operator, will this week reveal whether it is to go ahead with plans to enter the potentially hazardous US online gambling market. Chris Bell, Ladbrokes' chief executive, is understood to be keen to enter the US market. But the arrest there in July of David Carruthers, chief executive of rival BetonSports, on charges of racketeering, fraud and tax evasion, may have forced Bell to rethink his plans.