OSLO, September 4, 2008 (AFP) - Norway's public railway company NSB said Thursday two engineering companies, reportedly France's Alstom and Canada's Bombardier, had complained over its decision to hand a massive train contract to their competitor, Stadler of Switzerland.

'We have received two letters from two constructors whose trains were not chosen,' NSB spokesman Aage-Christoffer Lundeby told AFP, without naming the companies.

Financial daily Dagens Naeringsliv (DN) however reported Thursday that representatives of Alstom and Bombardier had protested NSB's decision last month to attribute a 500-million-euro (725-million-dollar) contract for 50 passenger trains to Stadler.

In addition to the 50 Stadler Flirt train sets, scheduled for delivery in 2012, the contract, which was signed on Tuesday, also gives the Norwegian company the option to purchase an additional 100 train sets.

'We have sent a protest letter to NSB,' the head of Bombardier's Swedish division Klas Aalberg told DN.

'In the letter, we evoke the selection procedure and we request information about the reasons that motivated NSB's choice. From the beginning of the tender process we felt there was a certain bias,' he said.

Sture Dramstad of Alstom's Norwegian unit also told DN he had sent a similar complaint to NSB.

'We respect their wish to receive clarifications and we will send them a comprehensive reply,' NSB's Lundeby said.