UPDATE 1-Polish government to approve draft shale law next week

* Law keenly awaited by shale gas investors

* Publication postponed in past few months

* Firms including Chevron, Marathon hold licenses

(Adds background)

WARSAW, Oct 9 (Reuters) - Poland's government will approve along-awaited new shale gas draft law next week, hoping toprovide a stable legal environment for investors interested inexploring the reserves, Prime Minister Donald Tusk said onTuesday.

Poland, which hopes tapping into previously inaccessibleshale gas reserves will reduce its reliance on costly gassupplies from Russia, has postponed the publication of the lawseveral times in the past few months.

"The assumptions are ready. We will be approving this draftat the government's sitting next week," Tusk said at a newsconference.

The draft law will then need to be passed by parliament.

Tusk said the draft required striking a balance betweenensuring state control and a fair distribution of the cashgenerated from shale gas, and keeping the rules liberal enoughto attract private investors.

Piotr Wozniak, deputy environment minister responsible forthe draft bill, said last week Poland wanted the law to go intoforce next year, but added that it would be best if a shale gastax waited until at least 2016.

Poland relies on Russia's Gazprom for over half ofthe gas it consumes. Warsaw wants commercial production of shalegas to start as soon as possible so it can limit thisdependence.

The shale gas law is eagerly awaited by companies holdingshale gas exploration licences including Chevron andMarathon Oil , as well as Polish companies such as PGNiG

and PKN Orlen .

Poland granted 111 shale exploration licences even as othercountries, including France and Bulgaria, halted shaleexploration pending further environmental studies.

Poland had high hopes for shale after a study by the U.S.Energy Information Association in 2011 estimated Polish reservesat 5.3 trillion cubic metres, enough to cover domestic demandfor some 300 years.

But estimated reserves were slashed to about a tenth of thatin a government report published in March.

(Reporting by Maciej Onoszko; Editing by Alison Birrane)

((maciej.onoszko@thomsonreuters.com)(+48 22 653 97 11)(ReutersMessaging: maciej.onoszko.reuters.com@thomsonreuters.net))