SEOUL, Jan 22 (Reuters) - Seoul shares extended losses by midday Friday, dragged down more than 3 percent by sharp declines in banks and technology stocks. The Korea Composite Stock Price Index was down 3.06 percent at 0416 GMT to 1,669.29 points. KB Financial Group fell 4.27 percent after its U.S. peers declined on restriction concerns, while LG Electronics shed 3.54 percent.