RadioShack Corp. is mired in negotiations with its lenders over plans to close as many as 1,100 stores, complicating the struggling consumer-electronics retailer's turnaround efforts, the Wall Street Journal reported today. The delay also is intensifying tensions with some lenders, who were surprised by the store-closing plan when RadioShack publicly disclosed it on March 4. The company, which operates about 4,300 stores in the U.S., said at the time that the plan still needed permission from its lenders, adding that its credit agreements allowed it to close only about 200 stores without the approval of lead lenders Salus Capital Partners and GE Capital, a unit of General Electric Co. The company also said in March that it planned to spend the next month hammering out an agreement with its lenders before choosing a liquidator to wind down the stores.