Sales fell by 5% at insurer Prudential during the first quarter following a sharp drop in business in Asia.Total insurance sales dropped to £697m in the first three months of 2009 from £732m a year ago, but slumped 11% in Asia, or 26% in local currency, to £333m. "Although we expect market conditions to continue to be challenging for the remainder of 2009, Prudential remains firmly committed to growing profitably in Asia and believes the long term growth potential of the region remains excellent," it said Thursday.Jackson in the US was up 12% to £184m thanks to positive currency moves, but the UK saw total sales drop 6% to £180m. The M&G business, Pru's UK asset management arm, enjoyed net inflows of £2.5bn, more than four times the £0.6bn achieved in the first quarter of 2008.Almost three quarters of gross inflows were for bond funds, up from 24% a year ago.Pru said its capital position remains strong, with its Insurance Groups Directive (IGD) capital surplus estimated at £2bn, which includes the £400m raised during May from a debt placement.This is expected to grow to £2.8bn once the transfer of the firm's Taiwanese agency business to China Life is complete, probably next month.