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LONDON/FRANKFURT, Dec 13 (Reuters) - Goldman Sachs Infrastructure Partners, London-listed 3i Infrastructure and Ilmarinen pension fund are selling Finnish power grid company Elenia Oy to Allianz Capital Partners, Australian infrastructure investor Macquarie and the State Pension Fund of Finland.
The companies declined to comment on the valuation on Wednesday.
But two sources familiar with the matter said the price equated to an enterprise value - debt plus equity - for the whole of Elenia of around 3.5 billion euros ($4.2 billion), making it one of Europe's biggest infrastructure deals of 2017.
The deal follows several sales of regulated grid businesses in recent years as European energy companies have sought to cut debt and raise funds for new infrastructure projects.
Grid deals have been sensitive in Finland. State-controlled Fortum recently sold all its Scandinavian distribution assets for 9.3 billion euros in a move which was followed by significant price hikes in Finland by Caruna, a new company formed to operate the grid.
The Macquarie and Allianz consortium beat competition from China Southern Power Grid and a group of investors including Queensland Investment Corporation (QIC) and the Netherlands' second-largest pension fund PGGM, according to people familiar with the matter.
Allianz and Macquarie are taking 45 percent each in Elenia, while the state pension fund Valtion Eläkerahasto is acquiring 10 percent. Completion of the transaction is expected during the first quarter of 2018.
3i Infrastructure said the sale of its 39.3 percent stake in Finland's second-largest power company would generate gross proceeds of about 725 million pounds ($968 million).
Elenia made a core profit of 168.4 million euros last year on revenue of 315.3 million euros. It serves 420,000 customers in central Finland.
Since the 3i Infrastructure-led consortium acquired Elenia in January 2012 for around 1.5 billion euros, the business has invested over 600 million euros aimed at increasing weather proofing of the network to improve reliability of electricity supply for customers.
"We look forward to our partnership with Allianz Capital Partners, MIRA (Macquarie Infrastructure and Real Assets) and Valtion Eläkerahasto who will support our continued investment program focused on weather proof distribution of electricity and continuous development of digital services for our customers," Elenia chief executive Tapani Liuhala said.
Elenia was founded in 2012, when Sweden's Vattenfall sold its Finnish power grids.
($1 = 0.7491 pounds)
($1 = 0.8506 euros) (Additional reporting by Jussi Rosendahl in Helsinki and Radhika Rukmangadhan in Bengaluru; Editing by David Evans and Ed Osmond)