Sprint and T-Mobile US were tipped to attempt to push through a merger deal without selling any of their assets, a move which could result in difficult negotiations with US antitrust and telecommunications regulators, Reuters reported.

The operators are keen to retain as much of their spectrum holdings and potential cost synergies as possible before regulators request concessions, Reuters explained, adding regulators can only start to review a merger once it is officially announced.

T-Mobile and Sprint are working on a strategy to deal with demands regarding asset sales, likely to include the divestment of some of their spectrum licences.

Craig Moffett, founding partner at MoffettNathanson Research, told Reuters the operators would be better off consulting regulators to assess and address their concerns before attempting a deal.

Last week, staff at the US Department of Justice (DoJ) were tipped to rule against approving a merger of the third and fourth largest US operators.

Sources said full time officials (who are not appointed by the governing administration) would prefer T-Mobile remains a disruptive force in the market with aggressive promotions.

A merger deal between the two would have to pass scrutiny from the DoJ as well as the Federal Communications Commission (FCC).

It is possible the operators will place a cap in their agreements on the size of divestitures they would be willing to accept.

UBS telecom and cable analyst John Hodulik said earlier this month the FCC could force the operators to sell spectrum, since together they would have the most airwaves in the US, with more than 300MHz.

This level of spectrum is crucial, especially for 5G.

The Reuters report also said a breakup fee is yet to be added to negotiations.