Sky News reports the transatlantic carrier made a preliminary offer for the division earlier this week.

It follows speculation Lufthansa was looking at Condor, Cook’s German short-haul carrier.

Boss Carsten Spohr said its bid could eventually extend to the rest of Cook’s airline division, including its UK operation.

Wizz Air’s private equity backer Indigo Partners is also understood to be interested in Cook’s airline business, which was placed up for sale in February.

At the time, a Cook spokesperson told TTG the business was open to full or partial offers for the group airline.

Virgin Atlantic and Thomas Cook declined to comment when approached by TTG. Cook reportedly set a 7 May deadline for expressions of interest in its airline business.

A move for Cook’s long-haul operation would extent Virgin’s presence and slot network at Gatwick and Manchester airports, and give it access to routes from Glasgow in the summer.

Virgin is currently awaiting final regulatory approval for its proposed takeover and transformation of Flybe, in partnership with Stobart Group and Cyrus Capital, and its expanded joint-venture with Air France-KLM and Delta Air Lines.

Cook, meanwhile, put its airline business up for sale after its first-quarter loss grew £14 million to £60 million, while its net debt approached £400 million last December.

It proposes to trim its UK retail network this year to 566 stores with the closure of a further 21 stores, putting more than 300 jobs at risk.

Its focus will turn instead to its digital operation and distribution, and its growing own-brand hotel portfolio.

The business confirmed last week it was in talks with lenders over a reported £400 million “liquidity buffer” to protect against likely winter 2019/20 pressures.