An increasing demand for prescription drugs helped boost quarterly profit at Walgreen ( WAG) by 14%. The company's third-quarter earnings rose to $296.1 million, or 29 cents a share, compared with $259 million, or 25 cents a share, in the year-ago period. The latest earnings matched analysts' estimates. Results benefited from a litigation-settlement credit, the company said. Total sales rose to $8.3 billion. Prescriptions accounted for 63% of sales, and the total amount of prescriptions rose 15.5%. Comparable-store sales increased 8.2%, with prescription sales in comparable stores rising 11.5%, the company said. The company said it expects the coming years to be a high-growth period. However, the company said operating results for teh latest perios were below plan. Shares of the Deerfield, Ill.-based company were down 6.9% at $30 in early trading Monday.