AUSTIN, Texas — Whole Foods Market’s first-quarter net income surged 79% to $88.7 million, on an increase in customer visits and a rise in average transactions. The natural and organic foods grocer raised 2011 profit outlook on its strong results, which beat expectations.

Sales for the quarter, ended Jan. 16, increased 14% to $3 billion. Same-store sales were up 9.1%, the highest level in four years. On a conference call with analysts, Walter Robb, Whole Foods' co-CEO, said average weekly sales per store for all stores increased 9% to $621,000, translating to sales per sq. ft. of approximately $856. "We are proud that we are continuing to gain market share at a much faster rate than most public food retailers," Robb said.

Whole Foods opened three stores and expanded one store in the first quarter. It expects to open three new stores, including one relocation, in the second quarter. The company also recently signed leases in Ottawa, Canada; Danbury, Conn.; Jamaica Plain and Lynnfield, Mass.; Marlboro, N.J.; and San Antonio. These stores currently are scheduled to open in fiscal year 2012 and beyond.