The news boosted Staples' shares by 8.3 percent to $15.40 in premarket trading.
Smaller rivals have also shown some improvement on the profit front lately, with Office Depot
Many investors look at office supply retailers as a good gauge of the economy as demand for their products is closely tied to white-collar employment rates. Sales at all three chains have suffered in the weak U.S. economy, and the companies continue to keep a tight rein on costs to offset weak demand.
For the full year, Staples continues to see sales rising at a low-single-digit percentage rate.
Its net income rose to $176.4 million, or 25 cents a share, in the second quarter, from $129.8 million, or 18 cents a share, a year earlier.
Excluding a tax refund, it earned 22 cents a share. On that basis, analysts on average were expecting 19 cents a share, according to Thomson Reuters I/B/E/S.
Sales rose 5.2 percent to $5.82 billion, while analysts expected $5.65 billion.
For the full year, Staples now sees net earnings of $1.42 to $1.48 a share. In May the company cut its forecast to a range of $1.35 to $1.45 a share.
Excluding the tax refund in the second quarter, Staples sees full-year earnings of $1.39 to $1.45 a share.
(Reporting by Dhanya Skariachan; editing by John Wallace)