Alleged misdealings over a nuclear power plant project dented Lithuania's standing on a global corruption list, watchdog Transparency International said Tuesday, but the prime minister rejected the claim.

Rytis Juozapavcius, head of the organisation's Lithuanian chapter, spotlighted the Lithuanian Electricity Organisation (LEO LT), which is piloting a four-nation plan to built a new nuclear power station in the Baltic state.

"It's a prime example of bad public management. There was no bidding process for private sector involvement. Maxima, the major retail group, was picked and that was that," Juozapavcius told AFP.

But Prime Minister Gediminas Kirkilas -- who won office in 2006 pledging to battle the corruption that has long afflicted the ex-Soviet republic -- hit back.

He claimed Transparency International's Lithuanian chapter had "always been hostile" to his government, according to the news agency BNS.

"I believe that it (LEO LT) is one of the most transparent projects. No one can prove its lack of transparency. This is mostly based on presumptions and stories spread by opponents of the project," he said.

Kirkilas noted that the government had hired international bank HSBC to monitor the project, and that its representatives had "said at one of the government's meetings that the project was transparent."

Kirkilas' office declined AFP's requests for comment.

LEO LT was formally created in May by merging the state-owned energy companies Lietuvos Energija and energy grid firm RST with private grid company VST, owned by NDX Energija.

NDX Energija is part of the group that operates Maxima, the largest retail network in the three Baltic states of Lithuania, Latvia and Estonia.

The Lithuanian state holds a 61.7 percent share in LEO LT, while NDX Energija has 38.3 percent.

LEO LT, working with partners from Poland, Latvia and Estonia, is due to build a new nuclear facility to replace a Soviet-era plant which Lithuania agreed to shut down by 2010 under the terms of its European Union entry in 2004.

Lithuania was ranked 58th of 180 countries on Berlin-based Transparency International's annual corruption survey, published Tuesday.

In 2007, it had been 51st on the scale, which runs downwards from the cleanest to the most graft-ridden.

Transparency International lists perceptions of the degree of corruption as seen by business people and country analysts, and gives scores from zero for a high level of corruption to 10 for the most graft-free nations.

On that measure, Lithuania slipped from 4.8 in 2007 to 4.6 this year.