* Host city Wroclaw scraps stadium deal with Mostostal
* Wroclaw says rival Budimex likely to continue construction
* Mostostal still hoping to resolve situation
(Adds Prime Minister quote, Budimex detail)
By Patryk Wasilewski
WARSAW, Dec 30 (Reuters) - Joint hosts Poland's Euro 2012 preparations suffered a blow on Wednesday when one of the venue cities scrapped a deal with a company building a tournament stadium.
Wroclaw, one of four Polish cities hosting the finals, decided to end its agreement with Mostostal Warszawa <MOWA.WA> because of construction delays.
"I have came to the conclusion Mostostal is not able to finalise the construction in the agreed time and if we continue cooperation the risk that delay would be even bigger is very high," mayor Rafal Dutkiewicz told a news conference.
Mostostal <MOWA.WA>, whose shares on the Warsaw bourse dropped by seven percent to 59.35 zlotys after the announcement, said it was still looking to rescue the 730 million zlotys ($253 million) deal.
"We hope this whole situation resolves in a positive manner," media officer Kinga Drozd told TVP Info. "We will do everything to continue building this stadium."
However, the city spokesman Pawel Czuma said a consortium of Poland's Budimex <BMEX.WA> and Germany's Max Boegl was likely to be named as Mostostal successor.
The announcement casts another shadow over the preparations of joint hosts Poland and Ukraine.
UEFA, European soccer's governing body, has been frustrated by the slow progress of work in Ukraine and in May gave the country's four cities six months to show significant improvement. It later gave four Ukrainian cities the green light.
UEFA president Michel Platini also spoke of huge Ukrainian problems in airport infrastructure, transport networks and suitable accommodation for the expected mass influx of fans.
Poland had previously been praised for its preparations and Wednesday's news was the first real sign of problems.
Poland's Prime Minister Donald Tusk told a news conference on Wednesday he was confident that even if things went wrong in Wroclaw, Krakow a back-up city, would be ready to step up and host the games.
"I think this situation is a good decision. Anywhere we find an unreliable company, one which delays the work, or wants too much money for it, it should lose the job," Tusk said.
"Wroclaw is a city I love, but I also love Krakow, which is ready and waiting to organise games."
Sports Minister Adam Giersz was confident Wroclaw would finish the stadium's construction despite delays in time for the championships.
The tournament will be held in the Polish cities of Warsaw, Wroclaw, Poznan and Gdansk and Ukraine's Kiev, Lviv, Donetsk and Kharkiv.
(Additional reporting by Gabriela Baczynska, editing by Tony Jimenez and John Mehaffey. To query or comment on this story email firstname.lastname@example.org)comments