Jan 14 (Reuters) - British luxury carmaker Aston Martin (AML.L) on Friday named Doug Lafferty, finance chief of Africa-focussed fuel retailer Vivo Energy (VVO.L), as its new chief financial officer replacing Kenneth Gregor. Lafferty"s previous stints include three years as the CFO of Williams Grand Prix Holdings, owner of the Formula One team Williams Racing, and the development comes at a time Aston Martin"s Formula One team CEO and principal Otmar Szafnauer exited the team last week. read more Aston Martin said in December Gregor will step down due to personal reasons after about 18 months in the role. read more