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.

"Where TUI customers are booked on Thomas Cook Airlines flights and these are no longer operated, replacement flights will be offered," TUI's chief executive Friedrich Joussen said.

"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," he added. 

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. 

"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," the CEO said.

Meanwhile, nearly 15,000 Thomas Cook customers have been repatriated following the travel company's collapse, the UK's Civil Aviation Authority (CAA) has said.

The CAA completed 64 flights on the first day of the operation, bringing 14,700 people back to the UK.

It is expected to bring back 16,800 people on 74 flights today. 

About 135,300 passengers are expected to be brought back to the UK over the next 13 days.

The programme continues until Sunday October 6, with more than 1,000 flights planned. 

Thomas Cook customers are reminded to check for further information.