Whole Foods Market Inc on Tuesday reported higher second-quarter profit and said store sales have accelerated, and its shares rose more than 7 percent after hours.

The news from the largest U.S. natural and organic grocery chain dispelled concerns that its store sales were slowing due to competition and other factors.

Same-store sales, a key gauge of performance for retailers, rose 6.9 percent for Whole Foods' fiscal second quarter that ended April 14. So far this quarter, those sales are up 9.4 percent.

About three weeks into the second quarter, Whole Foods had said its same-store sales growth had cooled to 6.4 percent, dampened by winter storm Nemo and a shift in the day of the week of Valentine's Day.

This quarter's sales results got a 200 basis point boost from Team Member Appreciation Double Discount Day, but still showed the kind of improvement investors were seeking.

"Even though the 9.4 (percent gain) is more like a 7.4 (percent gain), it's still a pick up," BB&T Capital Markets analyst Andy Wolf said.

The Austin, Texas-based retailer reported second-quarter net income grew to $142 million, or 76 cents per share, from $118 million, or 64 cents per share, a year earlier.

Total sales grew to $3.03 billion from $2.67 billion.

The chain also raised its forecast for full-year earnings per share to a range of $2.86 to $2.89 from $2.83 to $2.87.

Shares in Whole Foods, which hit an all-time high of $101.19 in October 2012, were up $6.71 at $99.51 in extended trading.

(Reporting by Lisa Baertlein in Los Angeles; Editing by Toni Reinhold)