Jan 18 (Reuters) - Britain's International Distributions Services said on Thursday that it enjoyed its best Christmas performance in four years, with revenues rising 9.8% during the festive period, as UK customers returned to using its Royal Mail delivery services.

The group, which kept its annual forecast, also said it had appointed Michael Snape, the former finance chief of UK drugstore chain Boots, as its group chief financial officer, effective immediately. (Reporting by Yadarisa Shabong in Bengaluru; Editing by Subhranshu Sahu)