UPDATE 1-Thomas Cook strikes bank deal, gets winter buffer

* Terms of existing loans revised

* Secures new 100 mln stg facility as winter looms (Adds details, background)

LONDON Oct 21 (Reuters) - Thomas Cook has struck a deal with its banks as it seeks to recover from a string of profit warnings that has cost the holiday company its chief executive and shareholders their dividend.

Europe's second biggest tour operator, whose shares have lost three-quarters of their value this year, said on Friday it had amended the terms of its existing bank facilities, giving the group greater financial flexibility.

"In addition, we have signed a new short-term committed bank facility to provide an additional 100 million pounds ($157 million) of headroom around the seasonal cash low point at the end of December this year," the group said in a statement.

The company said the terms of an existing 150 million pound loan and a 850 million pound credit facility maturing in May 2014 had been amended, setting new levels in terms of how much debt and debt-related charges it can carry relative to earnings.

Thomas Cook scrapped its dividend last month as part of efforts to cut its debt substantially over the next 2 to 3 years. ($1 = 0.638 British Pounds) (Reporting by Paul Hoskins; editing by Kate Holton)