 Barclays PLC LSE:BARC will increase its loan book in the residential mortgage market this year, after agreeing to buy UK lender Kensington Mortgages, which could put it on a firmer footing to contend with market leaders such as Lloyds Banking Group PLC LSE:LLOY. The UK mortgage sector has traditionally been dominated by five major lenders, with Lloyds historically taking the biggest share of the market. 