Tom Marsico has feasted on Chipotle shares.

Undeterred by a higher price, the mutual fund manager has bought more than 10 percent of Chipotle Mexican Grill's stock, according to a document filed with regulators.

Shares of the "fast-casual" restaurant chain have risen 78 percent this year, prompting concerns they could be poised for a fall. The stock closed at $101.70 on Friday.

Marsico Capital Management, based in Denver less than a mile from Chipotle's corporate headquarters, declined to comment on the move.

Marsico, whose assets under management have swelled to $94 billion, has owned Chipotle before. The firm had roughly 760,000 shares in early 2006 but trimmed the position and finally eliminated it last summer.

Chipotle stock, however, kept reaching new heights.

This time, it's unclear exactly when Marsico started purchasing Chipotle, but the filing with the Securities and Exchange Commission indicates that the firm's holdings crossed the 10 percent mark in July. Marsico Capital did not own a single share at the end of March, according to a prior disclosure.

The approximately 1.5 million shares acquired by Marsico are worth $154 million, based on the latest price.

With that Chipotle stake, Marsico would be the second- largest shareholder behind -Fidelity Investments.

The company on Friday also divulged it added to its Vail Resorts position, raising it to 10.4 percent from 7.5 percent.

Marsico has built a strong long-term track record, which has attracted billions of dollars of investors' money.

This year, his Marsico Growth and Marsico Focus Funds have struggled relative to rivals. The Marsico 21st Century Fund, though, has fared well in 2007.

Critics have worried that Chipotle, spun off in 2006 from McDonald's, has grown too pricey. They cite an increase in competition in the sector, jitters about consumers cutting spending and insider stock sales.

Morgan Keegan's Robert Derrington last week downgraded the stock to "market perform."

Barron's ran a story on its Web site this week under the headline "Cash In Some Chipotle Chips."

Morningstar analyst John Owens, meanwhile, issued a caveat in his Aug. 1 research note.

"Chipotle faces intense competition in the restaurant industry," he said. "If the brand's appeal isn't as wide as we believe, Chipotle could face saturation sooner than we expect."

Still, Owens said he is a believer in the company.

"Chipotle has a very bright future, in our view," he wrote in the report. "We like the company's strategy of doing just a few things, but doing them very well, and we believe there's plenty of growth ahead."

Put Marsico in that camp, too, at least for now.

patonj@RockyMountainNews.com or 303-954-2544