* IMF-backed Romgaz sale set to launch by year-end
* Aims as much as 600 mln euros from stake
* In contrast to CEE, Romania imports less Russian gas (Adds analyst comment, estimated market value, energy minister)
By Radu Marinas
BUCHAREST, Oct 11 (Reuters) - Romania plans to offer 15 percent of its biggest natural gas producer for sale in a stock market debut this year, part of privatisation plans agreed with international lenders and which officials have said could raise as much as 600 million euros.
Investors have criticised Bucharest for being slow to reform an inefficient state sector, which is seen as holding back one of Europe's poorest economies and deterring foreign investment.
"Romgaz is a strategic company for Romania and can rightly be called the jewel of the crown of the Romanian energy sector, due to its track record of performance over time," Energy Minister Constantin Nita said in a statement.
"The quality ... and its growth potential make it the right choice to be a flagship for Romania as the first Romanian privatisation to be listed on the London Stock Exchange."
The company in a statement said it had named Goldman Sachs International and Erste Group Bank AG as joint global coordinators and joint bookrunners for the inital public offering, while Banca Comerciala Romana SA and SSIF Raiffeisen Capital & Investment SA were appointed domestic lead managers.
The company said it planned to apply for the shares to be traded on the Bucharest Stock Exchange and for global depository receipts (GDRs) to be admitted to the London Stock Exchange.
The offering is expected to be completed by the end of 2013, subject to market conditions, it added.
The sale is part of privatisation plans agreed by European Union member Romania and the International Monetary Fund, which has led aid deals for the country since 2009.
Government officials said earlier this year Romania aimed at raising as much as 600 million euros from the stake, which would mean the whole company was worth about 4 billion euros ($5.42 billion). Local media have said Romgaz could have a total market value of 2.5-2.7 billion euros.
Rival oil and gas group Petrom, controlled by Austria's OMV, has a market value of $7.6 billion and a share price which is about 5.4 times expected earnings per share this year, according to Reuters data.
Romgaz has a share of 50.1 percent of domestic natural gas output and supplied 41.7 percent of domestic consumption. The rest of the gas is extracted by Petrom.
"The Romgaz IPO is a step in the right direction and will help meet the commitments made by the government under the IMF agreement," said Mihai Patrulescu, Unicredit senior economist.
"However, the government will also have to implement structural reforms and fulfill its obligations."
The offer is open to institutional and retail buyers in Romania and qualified international institutional investors outside the United States. Investment fund Fondul Proprietatea will keep its 15 percent stake and the state no more than 70 percent.
Romgaz's core business segments include gas exploration, underground gas storage and electricity production.
In 2012, Romgaz produced 5.7 billion cubic metres of natural gas and is also the largest underground gas storage operator.
Its earnings before interest, tax, depreciation and amortisation (EBITDA) were 1.1 billion lei ($334 million) in the first six months of 2013 against 1.2 billion in the same period of 2012 on revenues of 3.8 billion lei.
Romania imports less than a third of its annual gas consumption from Russia and produces the rest in local fields. ($1 = 3.2929 Romanian lei) ($1 = 0.7373 euros) (Editing by Patrick Lannin)