Flight centre is upgrading its services to fight increasing online competition.

Shares for the ASX listed company fell up to 17% yesterday after it said underlying profit before tax would be between $355 to $365 million AUD for the year to June, at the bottom end of its targeted $360 to $390 million.

Flight centre New Zealand, Chief Financial Officer, Alvin Soh says an increasing number of online booking sites is making the industry a lot more competitive.

He says they're addressing the problem by introducing a 24 hour phone service and modernizing their stores.

But he remains adamant that customer service is what will continue to give them their point of difference.