Wild Oats Markets Inc. long has seemed like a plate of cold leftovers next to Whole Foods Market Inc., its bigger and higher-end rival in the burgeoning natural-and-organic-foods grocery industry. But it may just be the tastier stock.

That conclusion was bolstered by the stock market's reaction to last week's news that Wild Oats Markets wouldn't renew the contract of Chief Executive Perry Odak and Wednesday's announcement that he had quit. Though Mr. Odak, 61 years old, had led the Boulder, Colo., company through a five-year turnaround, the stock price rose both times. Mr. Odak was criticized for being too timid in trying to grab customers who favor Whole Foods' sprawling stores.

"Investors would be happier to see a mistake being made being too aggressive in new-store formats than to see the opposite, which is them being too conservative," says Eric J. Larson, senior research analyst at Piper Jaffray & Co. in Minneapolis, who rates the stock the equivalent of a "hold" and doesn't own it.

Wild Oats' annual sales-growth rate of 3 percent to 5 percent at stores open at least a year lags behind the 7 percent to 9 percent average for the natural and organic industry, Mr. Larson says. Whether it can catch up may depend on who permanently succeeds Mr. Odak. The company said Gregory Mays, who became chairman after joining the board in July, will be interim CEO until it hires a successor. In 4 p.m. composite trading on the Nasdaq Stock Market, the stock was up nine cents to $17.80.

It is unclear whether billionaire Ron Burkle's investment firm, Yucaipa Cos., Wild Oats' largest shareholder, played a role in Mr. Odak's departure. The interim CEO, Mr. Mays, also serves on the board of Pathmark Stores Inc., a supermarket chain that also counts Yucaipa as its largest shareholder. Wild Oats spokeswoman Sonja Tuitele says that as far as she knows, Yucaipa had no involvement. A Yucaipa spokesman didn't return calls.

Mr. Odak, who also left the board, couldn't be reached for comment.

Wild Oats was founded in 1987 by Michael Gilliland and his wife, Elizabeth Cook, who purchased a vegetarian food store in Boulder. In 1991, they opened their first supermarket-size store in Santa Fe, N.M. They renamed the company Wild Oats Vegetarian Market and began buying smaller stores. They eschewed high-brow touches like offering extensive prepared foods and premium-cut meats that fast-growing Whole Foods embraced.

After an initial public offering in 1996, Wild Oats grew mainly through acquisitions and wound up with stores with nearly 20 names. When Mr. Odak took over in 2001, the company had $893.2 million in sales but was 90 days from a bankruptcy-court filing, executives say. Mr. Odak closed underperforming stores, announced layoffs and hired managers from PepsiCo Inc., Gap Inc. and his former employer, Ben & Jerry's. He experimented with store formats, including some nearly a third larger than the company's average.

The company now has 114 stores in 24 states and Canada, mostly called Wild Oats Natural Marketplace or Henry's Farmers Markets. Last year, it posted sales of more than $1 billion. Its market capitalization has grown to $521.8 million as its shares have more than doubled since 2001.

Whole Foods remains far ahead in terms of size, with 187 stores in the U.S., Canada and the United Kingdom, and sales last year of $4.7 billion. Its stock, which was up 55 cents, or 0.9 percent, to $65 a share Wednesday in 4 p.m. composite trading on the Nasdaq Stock Market, has more than tripled in the past five years, but it is trading far off last year's peak of $79.90 in December. Its total market value is $9.1 billion.

Whoever takes the reins at Wild Oats has the opportunity to seize on American consumers' seemingly insatiable appetite for organic and natural foods. Both Wild Oats and Whole Foods face growing competition from mainstream grocers Kroger Co., Safeway Inc., and Wal-Mart Stores Inc. that are expanding their natural- and organic-food offerings, and companies like SuperValu Inc. that are opening free-standing outlets. Wild Oats has been mentioned by analysts as a potential takeover target for big grocers pursuing the free-standing strategy, a factor that could drive up its stock price.

Michael Krestell, a research analyst at M Partners in Toronto, says the average size of Wild Oats stores -- between 23,000 and 24,000 square feet -- presents a strong counterpoint to Whole Foods, which is increasingly opening 80,000-square-foot stores in suburban and ex-urban locales. The smaller stores, Mr. Krestell argues, allow Wild Oats to snatch up parcels of land in urban locations and put itself squarely in front of Whole Foods' core urban, educated and affluent consumer base.

"The result," says Mr. Krestell, "is a nimble real-estate-operations strategy that can be executed quickly." Mr. Krestell has a "buy" rating on the stock and owns some of it.

In its newer stores Wild Oats has doubled the size of its meats sections and started offering higher-quality cuts of meat and fresher fish, and placing them in more-attractive glass displays.

Andrew Wolf, an analyst at investment bank BBT & Capital Markets, in Richmond, Va., says Wild Oats hasn't made these improvements in enough stores -- a criticism that a new CEO could address. Wild Oats also still fails in one key highly profitable area where Whole Foods is supreme: prepared meals.

Wild Oats' Ms. Tuitele says many of the innovations will be introduced during remodels of existing stores.

There are other reasons to be optimistic about Wild Oats: The company has its own line of branded products, which are distributed in Chicago by Peapod, an Internet grocer. In September, the companies said they would expand that relationship to the Baltimore-Washington market. That will likely heighten consumer awareness of Wild Oats' brand, especially if the two companies move into other markets. That, in turn, could entice traditional grocers to begin carrying Wild Oats-branded products as they increasingly move to satisfy demand for such goods, analysts say.

"There's a huge opportunity in this market, and Wild Oats should be capturing its share of that opportunity," Mr. Larson says. "They've got all the right ingredients. It's just a matter of getting the proper execution."