TGI Fridays, the casual dining chain once known for its robust happy hour and singles audience, may be on the auction block.

Minnetonka-based Carlson, owner of the 48-year-old restaurant brand, announced Friday that its board of directors has authorized a review of “strategic alternatives” for Fridays, including its sale.

Carlson CEO Trudy Rautio said favorable economic conditions and Fridays’ improving position in the marketplace make this an “optimal” time to examine options for the restaurant, which has been an integral part of the hospitality giant’s core business for years.

“At this time, Fridays is performing as good as it has in a long time,” Rautio said in an interview. “We have all cylinders running well right now.’’

Restaurant industry observers agreed that the timing of family-owned Carlson’s decision to shop Fridays around couldn’t be better.

“It’s a great time to be a seller in the restaurant business,” said John Hamburger, president of the Minneapolis-based Restaurant Finance Monitor. “There’s a lot of capital out there and a lot of interest in acquiring restaurant chains.”

Fridays, which has an international presence and 934 locations, had revenue of $2.7 billion last year, which was up 5 percent from 2011 but still below prerecession levels. About half of the 565 U.S. locations are franchise-owned.

Carlson, whose other businesses include Carlson Wagonlit Travel and hotels such as Radisson and Country Inns & Suites, had total sales last year of $37.6 billion.

Fridays ranks fourth in the casual dining category, behind Applebee’s, Chili’s and Buffalo Wild Wings, according to Technomic, a Chicago-based research and consulting firm that tracks the food service industry.

Fridays has slowly been refining its look in the past two years to bring it more up to date and to live up to its motto: “In here, it’s always Friday.”

Fridays also had become more family-oriented, and the refurbished look was intended to boost revenue by appealing to a younger, single clientele that tends to spend more money on drinks than on hamburgers.

Rautio said 63 Carlson-owned restaurants have gotten makeovers and that those locations are doing volumes that are about 10 percent above their competitors.

Rautio also said the international restaurants are doing well. She said Fridays in Taipei is 60 percent above the market in sales, while the newest store in Shanghai, China, is doing exceptionally well.

Hamburger said private equity firms “have fallen in love” with restaurant chains and that an international presence is a strong asset for a brand.

“Fridays is in a category, casual dining, that is a little challenged right now, but they have had good success internationally,” Hamburger said. “This is probably as good a time as any for Carlson to be selling that business.”

Rautio said the decision to test the waters for Fridays was made by the board of directors at a recent annual retreat where all the company’s businesses are periodically reviewed.

The company has hired Piper Jaffray as its financial adviser for the review of options. Rautio said she expected the process to take three to six months.

Fridays’ existing management team remains on board, and it will be business as usual if no sale takes place, she added.

The first Fridays opened in New York in 1965 and is said to be the birthplace of the term “happy hour” and the cocktail known as “Long Island Iced Tea.” The early Fridays were known for their red barber-pole inspired decor.

In more recent times, the Fridays menu has featured Jack Daniel’s-inspired meats and sauces and exuberant staff members.