text:  finalizing a plan to fix its business that could result in the closure of hundreds of additional stores in the next three years. CEO Tim Wentworth told analysts Thursday morning that changes are imminent for about 25% of the company's stores, which he said were underperforming. The drugstore chain currently runs more than 8,600 in the United States. Wentworth said the company's plan could include the closing of a significant portion of some 2,100 stores. Keith Peters reporting.