Holiday giant TUI has said it is assessing the impact of rival Thomas Cook's collapse on its results and "preparing measures" to support affected customers.
Chief executive Friedrich Joussen said: "Where TUI customers are booked on Thomas Cook Airlines flights and these are no longer operated, replacement flights will be offered.
"We are currently assessing the short-term impact of Thomas Cook's insolvency under the current circumstances, on the final week of our full-year 2018-19 financial result."
In its full-year trading update, Tui insisted its business model was proving "resilient" in challenging market conditions.
But it cautioned over Brexit uncertainty hitting demand, competition between airlines and the previously-flagged hit from the grounding of Boeing's 737 Max 8 aeroplane.
The group continues to see full-year earnings falling by up to 26%, in line with the profit warning it made in March.
Mr Joussen added: "These external challenges will continue in full-year 2019-20 - therefore, we will focus on becoming more cost competitive in our markets and airlines business to protect and extend our market share where possible."