THE cost of attracting savers and the Eurozone crisis sent profits at Santander's UK arm tumbling by 20 per cent during the first half of the year. Pre-tax profits in the first six months were £141 million lower year-on-year at £549m, hurt by the cost of luring deposits with high savings rates, while it also saw wholesale funding costs rise due to Europe's sovereign debt woes. The Spanish-owned bank also continued its retreat from riskier parts of the mortgage market, shrinking its home loans book by almost £11 billion year-on-year to £152.3bn. Its share of the mortgage market has now fallen to 10 per cent as it cuts back on interest-only deals.