LONDON, May 30 (Reuters) - Shares in British Airways owner IAG fell more than 4 percent on Tuesday after a huge IT failure grounded hundreds of flights over the holiday weekend, leaving 75,000 passengers stranded and dealing a major blow to its reputation.
BA was forced to cancel its schedule from London's Heathrow, Europe's busiest airport, and Gatwick on Saturday after it said a power surge knocked out its computer systems, disrupting its global flight operations, call centres and website.
It struggled to recover on Sunday and Monday, but said it would be operating a full flight schedule at Heathrow and Gatwick on Tuesday.
Shares in IAG, which also owns carriers Iberia, Aer Lingus and Vueling, fell more than 4 percent in early deals on Tuesday, the first day of London trading after the holiday weekend.
They were down 4.3 percent at 588 pence at 0708 GMT, wiping half a billion pounds off its market value.
Reporting by Paul Sandle; editing by Kate Holton