Electronics retailer RadioShack Corp reported a higher-than-expected quarterly profit, bolstered by strong sales of its digital converter boxes, postpaid wireless and flat-panel televisions.

Same-store sales, or those at stores open at least a year, rose 5 percent due to the upcoming mandatory switch of all U.S. televisions to digital in 2009, which boosted demand for digital converter boxes.

First-quarter net income at the Fort Worth, Texas-based retail chain rose to $43.1 million, or 34 cents a share, from $38.8 million, or 30 cents a share, a year earlier.

Analysts expected earnings of 22 cents a share, before special items, according to Reuters Estimates.

The retailer, which has about 4,400 company-operated stores, almost 1,400 dealer outlets and nearly 700 wireless phone kiosks throughout the United States, has closed unprofitable stores and cut staff in recent years to turn around its business.

However, it faces a tougher industry environment as U.S. consumers spend less money on nonessential items in a deepening recession.

The retailer also faces tough competition from Best Buy Co Inc , and discounters such as Wal-Mart Stores Inc striving to boost sales of consumer electronics.

RadioShack, which also has about 200 company-operated stores in Mexico, said first-quarter revenue rose 5.6 percent to $1 billion.

Its shares rose $2 to $12.80 in premarket trading.

(Reporting by Dhanya Skariachan; Editing by Derek Caney and Maureen Bavdek)