Wpd said the group chosen to develop the site had selected an "unrealistic" foundation type. It argued the proposed jacket foundation would be unsuitable, due to the unsuitablity of the seabed for drilling.
It also claimed the GDF-consortium failed to fulfill a requirement to "minimise the crossing of cables" between the 62 Areva 8MW turbines.
The German firm is hoping the French government will reconsider the offers made during the May auction.
Shortly after the auction, Wpd launched legal action against the decision challenging "the technical and economical reliability" of the rival consortium's offer.
The GDF consortium includes EDP Renewables, French developer Neoen Marine and Areva.
Wpd, in a consortium with EDF Energies Nouvelle and Alstom, bid for the project against GDF's consortium. The two groups also applied to develop the 500MW Le Treport project, which GDF won.