In North Norway the dominant method of exchange for fresh and frozen fish at the ex-vessel level is by direct (contract) sale, whereby price is negotiated between fish processors and the fishermen. More recently, an auction for frozen fish has been introduced. In this paper we investigate the relationship of prices between these methods of exchange and, in particular, whether the prices develop in a stable pattern between auction and direct sale by means of a cointegration analysis. Monthly prices of size-graded cod and haddock landed in the period 1997- 2003 are analysed. For most months, frozen fish sold through auctions realised the highest price, followed by direct sales of fresh and frozen, respectively. Fish sold by auction exhibits a larger monthly variation in price than fish sold directly. Prices for cod were cointegrated to a larger degree than for haddock, and the cointegration was strongest for frozen cod. The analysis also demonstrates that the auction prices for frozen cod and haddock drive the direct sale prices of similar fish, both frozen and fresh, even though the quantity sold via direct sales is greater than that of auctions. Law of one price (LOP) and weak exogeneity were present for cod and haddock
