In a Securities and Exchange Commission filing made this past Friday, RadioShack stated that it will be losing more than 400 kiosks located in Sam’s Club stores across the country. The closures will result from an expiring contract between RadioShack and Wal-Mart Stores Inc., owner of the Sam’s Club chain. Sam’s Club will take over the operation of the kiosks by June 30th, when the contract is set to expire. RadioShack currently sells cell phones and service contracts through the aforementioned kiosks, and it represents a decent chunk of business for the retailer — through the first nine months of 2010, RadioShack reported $20.6 million in profits from its kiosk business. RadioShack plans to increase the number of Target kiosks it operates in an effort to curtail losses, but the company estimates that its kiosk profits will still decline by between $10 million and $15 million in 2011.