Uber, the well-publicized San Francisco start-up that offers luxury transportation though a smartphone app, could be in regulatory peril less than a month after its D.C. debut.

In an interview Wednesday, D.C. Taxicab Commission Chairman Ron Linton said that Uber appears to be flouting volumes of city taxi and limousine regulations. The company is not registered with the commission, he said, and it is not clear whether its drivers are properly licensed. His comments came shortly after a commission meeting Wednesday, during which taxi drivers raised concerns about the new service.

Travis Kalanick, Uber’s chief executive officer, said Wednesday that he is confident his company is following all requisite laws and regulations. He noted that Uber does not directly own cars or employ drivers.

Uber is trying to occupy a market space somewhere between the taxi and the limousine. Uber rides are metered, like a taxi, using a proprietary smartphone-based system. But it is offering limo-level services in luxury sedans at a premium price: a $7 base charge, plus a $3.25 per mile and 75 cents a minute.

City regulations don’t have much to say about such a creature. If Uber were running taxis, it would have to use commission-approved time-and-distance meters and commission-set rates, and its drivers would have to hold hack licenses. If Uber were running limos, each trip would need a price set in advance and drivers would have to hold chauffeur licenses.

Uber operates a system that connects riders via smartphone with limousine companies that have contracts with Uber but are otherwise independent businesses. Those companies and their drivers, Kalanick said, are required by contract to have all the requisite licenses, registrations and insurance limo drivers are required to have.

Kalanick and Uber’s D.C. manager, Rachel Holt, said that they “had conversations” with representatives of the Taxicab Commission seeking clarification about D.C. regulations before Uber’s public launch Dec. 15.

“We would not have launched in D.C. if we were not confident and comfortable that we were doing right by the regulations and by our customers,” Kalanick said.

But Linton said he has “no record they ever approached our commission” about any aspect of doing business in the city. “No one has ever reached out to me from Uber,” he added. “Who are these guys kidding?”

Kalanick said the conversations took place “at a lower level” with commission staff.

The District’s mayor has broad authority under law to “issue any reasonable rule relating to the supervision of passenger vehicles for hire he or she considers necessary for the protection of the public.”

As those regulations stand, Uber cars would seem to fall under the definition of limousine — “motor vehicle carrying passengers for hire in the District, designed to carry fewer than nine (9) passengers, excluding the driver, with three (3) or more doors, other than a taxicab, coach, or wheelchair accessible van, and not permitted to accept street hails from prospective passengers in the street.”

This is not the first time Uber has run into regulatory questions. In October 2010, the San Francisco Municipal Transportation Agency and the California Public Utilities Commission issued a cease-and-desist order against the company’s San Francisco operations, but Uber has addressed the concerns and pressed on.

“We’re still operating in San Francisco and doing quite well out here,” said Kalanick, who added that he’ll be contacting Linton to address any concerns about Uber’s operations. “We have an office in D.C. We’re working with local businesses. We want to show them we’re operating within the regulations.”