Korea's large retailers saw their sales tumble by the biggest margin in eight years in January.

The Ministry of Knowledge Economy said sales last month at the country's three major retail chains -- E-Mart, Homeplus and Lotte Mart -- plunged by almost 25 percent from the same month last year. The Lunar New Year holiday, which fell in February this year rather than January, contributed to the drop, according to the ministry.

It also blamed the recession and the government's policy of forcing large retailers to close their doors for two days a month to protect small vendors.