(Reuters) - Cigarette maker Imperial Brands Plc on Monday appointed Stefan Bomhard as its chief executive officer, replacing Alison Cooper, as the industry faces a regulatory backlash against e-cigarettes and declining tobacco sales.Bomhard will join Imperial from British car dealership Inchcape , where he held the top role for five years. The company said his joining date will be announced later, while Cooper, whose departure was announced last October, has stepped down effective..