Britain's National Grid has awarded contracts totalling 1.5 billion euros ($1.7 billion) to companies involved in building the first electricity link between Britain and Norway, it said on Tuesday. Three international companies have agreed to build the interconnector, which National Grid said would be the world's longest at 740 km (459 miles), and run from Blyth, Northumberland, in Britain to Kvilldal in Rogaland, Norway.

The so-called NSN link will create a direct connection between the two countries' energy systems and have a capacity of 1.4 gigawatts. It is expected to be in operation by 2021. The companies awarded contracts are Italian cable supplier Prysmian, French cable supplier Nexans and power technology company ABB, which will deliver the convertor stations. The estimated cost of the project is between 1.5 billion euros and 2 billion euros, shared jointly by Norwegian transmission system operator Statnett and National Grid.

The link is aimed at providing additional electricity transmission capacity and it could help bring down electricity prices in both countries, National Grid and Statnett have said previously. "The benefits to both UK and Norway are also huge and when completed the link will deliver low carbon electricity for the UK and also add to security of supply for Norwegian consumers," Alan Foster, National Grid's director of European business development, said in a statement Tuesday.