Walgreen Co., the largest U.S. drugstore chain, said fiscal second-quarter earnings rose 19% to $283.3 million, or 28 cents a share, matching analysts' expectations, with help from higher prescription drug sales and new stores. Revenue grew 15% to $6.43 billion. The 100-year-old company opened 178 stores in the first half of the year in an effort to win more elderly customers and to better compete with CVS Corp. and Rite Aid Corp. Walgreen plans to nearly double its store count to 6,000 by 2010. The company had 3,343 stores as of Feb. 28 and said it will open 500 stores this fiscal year. Shares of Deerfield, Ill.-based Walgreen fell $1.22 to close at $39.56 on the NYSE.