XL Leisure Group is the third largest tour operator in the UK and operates a number of companies including XL Airways, Aspire Holiday, Freedom Flights, The Really Great Holiday Company and Kosmar Villa Holidays.
In February it signed a three-year deal, worth £2.5m per year, to sponsor the Premier League football club.
West Ham owner Bjorgolfur Gudmundsson is also caught up in XL's failure as the main shareholder of Landsbanki, one of the two Icelandic banks which financed the company. The club this week appointed former Chelsea and Italy legend Gianfranco Zola as its new manager after parting company with Alan Curbishley last week.
There is still hope that the administrators, thought to be insolvency specialist Kroll, could find a buyer for the travel business.
XL made an operating loss of £24m in the 12 months to October 2007.
Its fall follows the failure of package holiday operator Seguro earlier this week and a host of airlines including Zoom, Maxjet, Silverjet, Eos and Oasis this year.