T-Mobile announced in a filing with the US Securities and Exchange Commission on Monday that the two companies had agreed to extend the deadline for completing their planned merger to July 29. The previous deadline had been Monday.
In an interview on CNBC, Justice Department Antitrust Division chief Makan Delrahim said that the meetings were ongoing as regulators review the deal.
"I have not made up my mind," he told CNBC. "The investigation continues. We've requested some data from the companies that will be forthcoming. We don't have a set number of meetings or a time line.
"If the case is there for us to challenge a transaction or suggest changes, we will do that," he said, adding that the division is reviewing the argument that the merger will allow the combined company to produce faster next-generation wireless services.
The deal -- announced a year ago Monday -- comes at a time when the US carriers are bending over backward to win your business, with offers like unlimited data and freebies such as access to. Sprint is still . Those competitive pressures have driven T-Mobile and Sprint together. And while executives from both companies vow lower prices and better service, consumer groups and analysts are skeptical.