UPDATE 1-TNT costs up on air closures, switches to road network

* Says too early to specify extra costs

* Has three planes bound beyond Europe grounded

* TNT shares down 1.5 pct

(Adds spokesman's comments, details, shares)

AMSTERDAM, April 19 (Reuters) - Dutch mail group TNT TNT.AS said on Monday it had switched to road transport in Europe after the closure of European airspace, but was incurring higher costs due to delays and the grounding of its planes.

Large parts of Europe enforced no-fly rulings for a fifth day on Monday because of a huge ash cloud from an Icelandic volcano that has caused the worst air travel chaos since the Sept. 11 attacks. [ID:nLDE63I007]

TNT, Europe's second-largest mail and delivery company, operates its European air operations from Liege in Belgium and spokesman Cyrille Gibot said TNT had been hit with higher operating costs, but it was too early to say by how much.

"TNT's air network is mainly a European network. Within Europe we have a very strong road network that covers 39 countries, which means for most of the freight we have been able to move it by truck," Gibot said, adding TNT has so far been able to process about the same amount of volumes.

TNT shares were down 1.5 percent at 22.66 euros at 0904 GMT, underperforming the Amsterdam AEX index .AEX, which was down 0.5 percent.

But Gibot added TNT's two Asian-bound flights were still grounded and loaded and ready to fly as soon as possible. The plane TNT operates for New York-bound flights with a partner is stranded in Iceland and first needs to return to Liege.

"Planes and crews are ready to fly again as soon as the skies open, so we're waiting for the outcome of the European commission meeting today to make a final decision today on whether we have to cancel the flights this evening."

Moving to road transports has led to some delays for TNT clients and extra operational costs linked to measures and precautions to deliver time-sensitive goods, such as medical or pharmaceutical samples.

TNT usually flies to 63 airports in 26 European countries and four airport outside of Europe. (Reporting by Aaron Gray-Block; Editing by Louise Heavens)