UPDATE 1-Snam, Fluxys buy Eni assets to build gas network

* Deal worth overall 150 mln euros

* Snam, Fluxys aiming to create European gas network

* Eni selling non-core assets (Adds detail, background, shares)

MILAN, Feb 23 (Reuters) - Italy's Snam and Belgium's Fluxys have agreed to buy the stakes that oil and gas giant Eni holds in a series of gas assets in northern Europe as the two companies press ahead with plans to create a European gas transport network.

In a joint statement on Thursday Snam and Fluxys said they would pay 150 million euros for Eni's stakes in three assets, including a 16.4 percent stake in Interconnector (UK), the underwater pipeline linking Britain with Belgium.

They will also buy Eni's 51 percent stake in facility provider Interconnector Zeebrugge Terminal and its 10 percent stake in Huberator, which provides trading services at the Zeebrugge gas hub.

"Today's agreement is the first step towards Snam becoming a major integrated player in the European regulated gas business," Snam Chief Executive Carlo Malacarne said.

In January Snam and Fluxys signed an agreement to assess joint initiatives to develop gas infrastructure projects and to help create a south European gas hub.

Italy is heavily dependent on gas imports for its energy needs with pipelines to Algeria, Libya and Russia. It is developing infrastructure projects to import gas from Azerbaijan.

Snam, Europe's biggest regulated gas operator, is gearing up for a big push outside its domestic market, after a reorganisation of its business and new European regulations.

The company, which is 52 percent controlled by Eni, has previously said it has 1.5 billion euros available for investment opportunities in Europe.

Fluxys, the operator of Belgium's network of natural gas pipelines, aims to become a major European gas transmission infrastructure company, taking on Dutch-based Gasunie.

The company's acquisition of Eni gas transport pipelines last year made it a major force in European gas infrastructure, giving it pipelines extending from Belgium to Italy via Germany and Switzerland.

Eni, which is planning to sell down its stake in Snam, is selling non-core assets to focus on its more profitable exploration and production business. (Reporting by Stephen Jewkes. Editing by Mark Potter)