A Denver-based Mexican restaurant food chain will be the anchor tenant for a former downtown office building being remodeled for retail, office and apartment uses.

Company officials said Wednesday they plan to open Qdoba Mexican Grill by May in the former Connex International building at 947 Mass.

The remainder of the building’s main floor will be occupied by a wireless phone provider; two upper floors will house a mix of office suites and apartments.

“We think the project will bring exactly what downtown and the city is after,” said Doug Compton, a Lawrence developer leading a group of investors redeveloping the building. “It is a good mixed-use project.”

The restaurant is a fast-service chain, but more like a Chipotle Mexican Grille than a Taco Bell, said Todd Owen, director of franchise development for the company.

“No one will confuse our food with Taco Bell,” Owen said. “We charge more for it and it is healthier and much more customized.”

Owen said the company, which will open about 100 stores in 2004, targets communities like Lawrence.

“We do well in slightly above-average income towns and we skew to a slightly higher education base,” Owen said. “Lawrence being a college town fits well into our demographics too. We think college students are shifting faster out of fast food than they ever have before.”

Work is under way to convert the former Connex International building into one of the downtown's larger mixed-use developments. The ground floor of the building, 947 Mass., will house a Mexican restaurant chain and a wireless phone store. Plans call for the second floor to include two office suites and the third floor will be filled with six loft-style and one-bedroom apartments.

The restaurant, which will employ about 15 people, will occupy about 3,600 square feet on the building’s first floor.

Compton said Mobile Communications, a wireless phone store with a location at 1610 W. 23rd St., would take the remaining 1,600 square feet on the first floor. It was uncertain whether the 23rd Street store would remain open. Attempts to reach a representative with Mobile Communications were unsuccessful.

Compton said the second floor was expected to have two office suites and the third floor was expected to have six apartments, with a mix of one-bedroom and loft-style units.

The building formerly was the home of Connex International, a firm that arranges teleconferencing calls for companies across the country. When Connex moved last year to 23rd and Harper streets, Compton and partners bought the 95-year-old building to convert it into one of the downtown’s larger mixed-use developments.

Compton said design plans for the 15,000-square-foot building included adding more ground floor windows and other interior details to make it look similar to its original 1908 design.

“It is a pretty big piece of real estate,” said Kelvin Heck, a commercial real estate agent with Grubb & Ellis/The Winbury Group and the leasing agent for the project. “We’re hoping it becomes an anchor for the south end of downtown.

“With the apartment component, it is really a good thing for the vitality of downtown. It makes downtown more of a 24-hour location.”

Compton said rental rates for the six apartment units hadn’t been set. He said the ground floor renovation should be complete in April, the office space by May and the apartment units by August.