Sears had ownership in Prodigy, one of competitors to AOL in the 90s, but the new owners sold their interest and decided to complete with Walmart and Target in the discount store race (remember Sears Grand?). Then they got stupid and merged with K Mart.
The sale to K Mart was a strategic move by the Sears Board of Directors. By selling themselves to K Mart Sears was able to cabcel their Defined Pension for their employees, thus shedding all that liability they had accrued. Since almost no corporation ever had their Defined Pension programs fully funded they were all liable for the shortfall.
Selling to K Mart allowed them the opportunity to dump that liability.