UPDATE 1-Eni hopes to crack tight-knit French retail gas market

* Eni says aims to reach 500,000 customers in 2016

* Says hopes to be profitable in France "very quickly"

* New Belgian offers to follow next week

(Adds quotes and background, changes dateline from MILAN)

PARIS/MILAN, Oct 9 (Reuters) - Italian oil and gas group Eni

launched a retail gas offer in France on Tuesday, hoping to triple its number of customers by 2016 in a tightly-knit market still dominated by former monopoly GDF Suez .

France's energy market opened up to competition in 2007 but state-controlled tariffs for gas and electricity make it difficult for newcomers to beat GDF Suez and EDF .

Eni, whose market share in France stands at 1.6 percent, unveiled four offers including one at a guaranteed 6 percent discount on French regulated tariffs, still favoured by 90 percent of French households.

Eni said it hoped to bank on its reputation as a large, integrated oil and gas group and planned a 20 million euro ($25.9 million) advertising campaign to convince French consumers so far reluctant to switch to little-known competitors.

"Why would the French consumer be tempted by the competition today even though the market was opened five years ago?" Eni Gas & Power Chief Executive Mauro Fanfoni asked reporters rhetorically at a presentation below the Louvre museum's glass pyramid in Paris.

"Consumers only had a choice between the former monopoly and new, alternative operators, which were certainly attractive but were often considered too fragile," he said.

In addition to GDF Suez's own unregulated offer, French consumers have seen the arrival of smaller players such as Poweo

and Direct Energie, but the two companies failed to reach a critical size and announced a merger last year.

Eni has to date been operating on France's retail market through the Altergaz brand.

Fanfoni said the group's aim was to reach half a million residential customers, or a market share of 5 to 6 percent, in the next four years.

The second-largest gas supplier in France with 14 percent of overall gas deliveries, Eni also owns the Agip network of petrol stations in the south of France, which it said it would expand under the Eni brand.

Cristian Signoretto, a senior executive at the group's gas and power division, said at the event Eni would also launch similar offers in Belgium next week and planned to serve 12 million households in Europe in 2015 from 9 million today.

Asked when Eni's retail gas business could become profitable in France, Fanfoni said: "With the current tariffs envisaged by historical operators ... we will be profitable very quickly." ($1 = 0.7711 euros)

(Reporting by Michel Rose and Stephen Jewkes)

((michel.rose@thomsonreuters.com)(+331 4949 5570)(Reuters Messaging: michel.rose.thomsonreuters.com@reuters.net))

Keywords: ENI FRANCE/