posted better-than-expected earnings growth, pushing the office-supply retailer's shares up 4.5%.

The company posted fiscal fourth-quarter net income of $165 million, or 35 cents a share, up from the 33 cents a share expected by Wall Street and 21% better than the 29 cents a share reported in the year-earlier quarter. Sales rose 14% to $3.3 billion.

"Staples had a phenomenal year," said Ron Sargent, Staples president and CEO. " We now look to build on our momentum, capitalize on the investments we made this past year, and deliver sustainable results going forward."

The company reiterated estimates of 16 cents a share in profits for the next quarter, in line with analyst forecasts.

Staples shares climbed 75 cents to $17.35 in premarket trading, according to Instinet.