* Traders welcome official ban instead of informal barriers
* Recent deals with Egypt's GASC in doubt
* GASC warns Ukraine on international credibility
* Ukraine focuses on maize exports (Adds EU farm chief reaction)
By Pavel Polityuk and Maha El Dahan
KIEV/ABU DHABI, Oct 24 (Reuters) - Ukraine's agriculture minister on Wednesday said the country would ban wheat exports from Nov. 15 after a weather-damaged harvest, a move that underpinned international prices.
Egypt, the leading global wheat importer, warned that Ukraine risked damaging its credibility on international grain markets. Ukraine later said existing contracts can be fulfilled.
"There will be a full ban from Nov. 15. There will be a government order about this. We are not playing games here. We do not have any other option," Farm Minister Mykola Prysyazhnyuk told Reuters, confirming widespread speculation in markets in past weeks.
The European Union's top farm official warned Ukraine to avoid any measures that would increase global grain prices and disturb traditional trade flows.
"I am deeply disappointed to see this announcement ," EU A g riculture C o mmissioner Dacian Ciolos said in a statement. " I t will add unnecessary tension to international agricultural markets, and those that will suffer most will be the world's poorest."
Ukraine, one of the top 10 global wheat-exporting countries, saw its harvest slashed by a third this year due to poor weather, as the United States suffered its worst drought in more than half a century. Global prices of wheat, corn and soybeans raced up sharply over the summer period.
