Reuters Holdings Plc is reorganizing into three the four business divisions that make up its UK & Ireland operation. The unit, which had 1995 sales of 435m British pounds, will create National, International, and European divisions to replace its existing City North, South East and West divisions. The changes will take place progressively from January 1. The National division will be responsible for all UK and Irish banks and institutions, all money brokers and the four regional offices. International will manage all Asian, mainly Japanese, and US clients, plus customers in the shipping business, while European will be responsible for clients in the commodities markets, plus all European clients in London.