Norway's controversial new salmon farming tax was approved by the country's Parliament (Stortinget) by a slim margin because of the overall weakness of the taxation plan, said several salmon farming executives.

On Thursday, final details surrounding the new aquaculture tax were announced by the Norwegian government.

In the updated proposal, the tax rate will be set at 25 percent, which is lower than the 35 percent proposed in March, and below the 40 percent called for in the initial proposal first announced in September.