UK's Harbour Energy falls after shareholder sells part of stake at discount
** Shares of British oil and gas producer Harbour Energy HBR.L fall as much as 11.3% at 251.4p ** Stock among top losers on FTSE midcaps index .FTMC ** Co's third largest shareholder EIG Asset Management, sells 60 million in co at 255 pence per share ** Placing at 10% discount to last close ** EIG currently holds a 7.3% stake in HBR ** YTD, stock has risen ~30% (Reporting by Tuhina in Bengaluru) ((tuhina@thomsonreuters.com))