AT&T Georgia is suing Atlanta and MARTA for millions of dollars it says it’s owed for relocating utilities to make way for the city’s new Streetcar.

In a lawsuit filed in Fulton County Superior Court last month, the telecommunications company said it spent $5.8 million when it was ordered to relocate its equipment, such as cables, wires and conduits, ahead of streetcar construction. AT&T also said in the filing it’s concerned about future costs because of the potential for streetcar expansion.

The city and MARTA have so far refused to pay, according to the filing, because they believe that Atlanta has “the inherent authority” to force AT&T to move its equipment. They have also rejected AT&T’s position that state law requires reimbursement to utility companies for MARTA-related rapid transit expansion.

A spokesman for the telecommunications giant indicated suing was a last resort.

“After multiple attempts over more than two years to resolve the issue of reimbursement for expenses to relocate our network facilities to accommodate the Atlanta Streetcar project, we have been unable to reach an agreement and now seek assistance from the court,” AT&T Communications Director Lance Skelly said.

Mayor Kasim Reed’s office disputes AT&T’s contention that the city owes the company money.

Reed spokeswoman Anne Torres released the following statement Wednesday to The Atlanta Journal-Constitution:

“The city has consistently maintained for over two years that AT&T is not entitled to any reimbursement from the city. The city will vigorously defend this position and remains confident that it will prevail in a court of law.”

AT&T contends the streetcar is essentially a MARTA project, and therefore subject to the MARTA Act of 1965, which requires the transit agency to reimburse utility companies when they are forced to move facilities for rapid transit expansion.

The city and MARTA, along with the Atlanta Downtown Improvement District, are partners in the $96 million project. While Atlanta owns and operates the streetcar, MARTA effectively oversees the system.

AT&T also said that per the city’s intergovernmental agreement, the cost of moving utility equipment can be paid out of grant money awarded to the streetcar project. The streetcar was funded, in part, by a $47 million federal transportation grant.

It’s unclear what the dispute could mean for future rapid transit expansion. The four-car system now operating from the King Center to Centennial Olympic Park is phase one in a much larger plan. In the filing, AT&T said it anticipates additional future costs from that growth.

Several mom and pop shops along Edgewood and Auburn Avenues have said their businesses suffered as the city built the 2.7-mile streetcar track in downtown Atlanta — a sales slump many expect will reverse now that the streetcar system is up and running.

The streetcars were originally scheduled to become operational in May 2013, but the project faced repeated delays over safety concerns and major cost-overruns before opening late last month.