* Woodside joins intl oil & gas majors looking to Myanmar
* Move into Myanmar expands Woodside's intl portfolio
* Myanmar still risky but more investment likely
MELBOURNE/PERTH, Oct 19 (Reuters) - Woodside Petroleum has agreed to explore for oil and gas in Myanmar with South Korea's Daewoo International Corp, giving Australia's biggest oil and gas company a foot in the door in one of the global industry's most promising frontiers.
Woodside said on Friday that Daewoo International has agreed to sell it a 40 percent stake in a production sharing contract in Block AD-7 in the Rakhine Basin, in the western offshore area of Myanmar, next to Daewoo's Shwe gas field development.
The deal gives Woodside a leg up over many other Western energy companies eager to get into Myanmar, which is opening up after nearly 50 years of military rule.
"Myanmar appears to be on the map of most players. The reserves are attractive compared with other Southeast Asian countries," Subramanya Bettadapura, Director, Energy & Power Systems, Asia Pacific, at Frost & Sullivan.
In September, France's Total acquired a 40 percent stake in an offshore block.
Myanmar is believed to be rich in natural gas reserves, which various government officials estimate to range between 11 trillion and 23 trillion cubic feet, or nearly 10 to 20 percent of world leader Australia.
It is also close to energy hungry markets such as China - which will begin importing gas from Myanmar next year - and India.
Gas already represents 57 percent of the Southeast Asian country's exports, but most foreign investment so far has come from China and Thailand. With the easing of U.S. sanctions, many Western firms are keen to invest in the country.
Woodside is among several companies, including ConocoPhillips, Hess Corp, Royal Dutch Shell , BP and BG Group, lining up for an oil and gas exploration tender that a senior energy official said could happen around the end of this year.
The tender, originally expected in September, was delayed as global oil majors insisted it meet their standards for transparency, in a sign of the challenges and risks that still await companies hoping to do business there.
A Woodside spokesman said details of the Daewoo agreement were confidential, and he declined to comment on the tender.
Industry insiders see the moves as part of a strategic shift from Woodside's domestic-only focus to include international projects, led by Chief Executive Peter Coleman who took the helm last year.
"After having withdrawn, under their previous CEO, quite significantly from their international focus... they are now looking further afield to supplement their Australian assets," said Anthony Patten, a partner at the law firm Allens in Perth who specialises in oil and gas.
The partnership with Daewoo, which acquired rights to three oil and gas blocks in Myanmar from 2000 to 2007, will not necessarily preclude Woodside from participating in further tenders, Patten added.
"In teaming with Daewoo, they join an experienced Myanmar player from day one," he said.
A Daewoo International spokesman said his company, which is active in international trade and resource development, had reached a provisional contract with Woodside and had not yet set a timeline for finalising terms.
Daewoo and Woodside plan to run seismic tests in 2013 and 2014 on the Rakhine block, with an option to drill an exploration well later.
"We would see more companies trying to get into Myanmar probably through partnerships," Frost & Sullivan's Bettadapura said, but added that despite Myanmar's recent openness to investment, it is still high risk.
"Myanmar definitely has a lot of risks. It's not completely opened up. You don't know what the policies would be unless there is a clear roadmap from the government."
Nobel Peace Prize laureate and opposition leader Aung San Suu Kyi has warned companies to avoid partnering with the state-owned Myanmar Oil and Gas Enterprise, due to its lack of transparency and accountability.