The weaker-than-anticipated sales at its pharmacy counters, generic-drug introductions and one less weekday in May, led to the May same-store sales at Walgreen Co. rising 1 percent, missing the estimated figures for the month. According to an average Thomson Reuters' forecast, analysts had expected the figures to rise at least 2.2 percent.

The mere 1.5 percent rise in the pharmacy same-store sales also remained below the analysts' expectations of a 3.5 percent rise.

However, with the same-store sales of general merchandise increased 0.2 percent, dramatically topping the analysts' expectations of a 0.2 percent fall, the total May sales at Walgreen increased 6.1 percent to reach $5.37 billion.

The generic drugs' same-store sales rose 1.5 percent, while same-store filled prescriptions increased 2.8 percent.

Walgreen, which is the second-ranking US store by store count - after CVS Caremark Corp. - is, at present, struggling to pull through a recent trend of weakened retail sales. Along with reporting the sales figures for May on Tuesday, the company also said that, as of May 31, it had 6,857 drugstores - the figures indicating 605 more stores in comparison to the year-before number of stores!