A source close to the company said the review of the UK business, which will be announced on Thursday, will include 200 store closures.
Thomas Cook has also hired an undisclosed company to conduct a consultation with customers about its brands, the source said.
In July Thomas Cook said it would undertake a "fundamental operational and strategic review of its business" following its third profit warning in a year and a month before its chief executive, Manny Fontenla-Novoa, left the company.
He was replaced by his deputy, Sam Weihagen, on an interim basis.
The 200 stores set to be closed are believed to include the 75 high-street shops Thomas Cook has previously revealed were to be axed.
A spokesman for Thomas Cook said: "Thomas Cook announced earlier this year that its new UK management team would be announcing the results of the UK review on the 24 November.
"As part of the review the management said it would announce measures to refocus the product strategy in mainstream package holidays, streamline the UK airline, improve yield management and operational excellence and measures to leverage the strong and trusted Thomas Cook brand.
"We will announce the outcome of all of these areas on Thursday."
Thomas Cook's review is intended to rejig its balance of online and offline bookings, as the tour operator recognises that the online market is playing "an increasingly important role" in its business, but claims high street bookings remain key.
The merger between the two travel companies will create a network of 1,300 high street stores.
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