(Sharecast News) - Surverying services firm Thalassa was on Friday advised by the Norwegian tax authorities that its appeal in relation to the 2014 tax year has been successful.Thalassa said it is now "cautiously optimistic" that the authorities will apply the same interpretation to its returns for the tax years between 2015 and 2017.Duncan Soukup, chairman of Thalassa, said: "Whilst the board was confident that the company's affairs were, therefore, compliant, there was no guarantee that the company would prevail in its appeal. As it happens, the company had failed in its appeal at the regional level and was obliged to take its case to the national tax authority."The AIM traded company has not received full details of the 2014 rebate but said that the amount that has been accrued annually and reflected in aggregate in trade and other payables in the 2017 Annual Report and Accounts is approximately $0.7m."The company was well prepared for the appeal process having sought professional advice and structured its affairs to ensure that the company's transfer pricing policies followed, where appropriate, relevant OECD (Organisation for Economic Co-operation and Development) transfer pricing guidelines," said Soukup.Thalassa's shares were up 1.13% at 89.50p at 1234 BST.