Five consortiums compete for E.ON's grid-sources

* GDF, Fluxys, Gasunie keen to secure gas supply from Russia-sources

* E.ON could fetch up to 3 bln euros-sources

* Data room access expected in March, binding bids in June-source

By Sophie Sassard

LONDON, Jan 19 (Reuters) - Five groups are expected to submit bids for German group E.ON's gas distribution network by Friday, sources close to the process said, setting off a fierce battle for the 3 billion euros ($3.8 billion) grid.

The network is deemed of high strategic importance for countries such as France, Belgium and Italy seeking to secure gas supply from Russia as the Nord Stream pipeline under development would directly connect Russia to Germany.

Grid businesses have become less attractive since the Europe Union asked companies to separate transmission and marketing and as regulators have borne down on the fees they can charge.

One of the consortiums putting in a non-binding expression of interest consists of GRTGas, a subsidiary of GDF Suez , French insurer CNP Assurances and the IFM Australian Infrastructure Fund.

This group could have an advantage as it already operates in gas transport in southern Germany through its joint venture with E.ON Megal.

But it could also face new antitrust hurdles, after Europe fined E.ON and GDF Suez 553 million euros each for market-sharing in French and German gas markets in July 2009.

Two "Canadian" consortiums were seen as the strongest financially, said one banker seeking a financing role in the process.

They are a combination of RREEF Infrastructure, Singapore's sovereign fund GIC and Canada's Borealis and a group consisting of Allianz, Canadian Pension Plan (CPP) and Dutch gas network operator Gasunie.

Italy's gas network operator Snam is considering joining Belgian peer Fluxys -- and Global Infrastructure Partners (GIP) -- in their bid, as the two recently signed an agreement to assess joint initiatives to develop gas infrastructure projects in Europe, one of the sources said.

A fifth consortium included Abu Dhabi Investment Authority (ADIA) and offshore investment advisory firm British Colonial.

Bidders have for now been asked to submit general expressions of interest. Price would be discussed at a later stage, one of the people said.

Bidders should be given access to the network's books in March and fully-financed bids could be submitted by the end of June, one of the people said.

The sale, which is run by Goldman Sachs, does not include vendor financing -- also known as staple financing -- this source said. Raising funding for this type of infrastructure asset should not be an issue.

E.ON wants to sell a raft of lower-margin assets following Germany's decision to abandon profitable nuclear power.

(Editing by Douwe Miedema and David Cowell)