* ConocoPhillips the only U.S. energy major left
* Low oil prices prompting exploration budget cuts
* Industry says subsidies could help
* Government says shale, energy security remain priorities
By Agnieszka Barteczko and Anna Koper
WARSAW, Feb 12 (Reuters) - Poland, once Europe's greatest hope for shale energy, is reeling from a rapid change in fortunes as U.S. companies walk away and low oil prices postpone any realistic start to commercial drilling.
Facing EU environmental targets in 2020 and beyond, Poland needs to find alternatives to burning coal. It also wants to reduce imports of Russian energy by producing more of its own.
Yet hopes that drilling for shale gas can replace these have dimmed, with Chevron the latest major energy company to quit Poland.
ExxonMobil, Marathon and France's Total have all been and gone.
A drastic cut in Poland's estimated shale gas reserves marked a first blow in 2012. A 50 percent drop in oil prices since last June has proved a second.
"For us the situation is dramatic. All projects have to be put on hold," said one manager at a small energy company in Poland, pointing to hundreds of layoffs as investors withdraw and servicing firms remain idle.
While exploratory drilling has been done, Poland has not delivered a single commercial well and the only global major company left is ConocoPhillips.
"We continue to evaluate results of our recent testing in Poland," said a spokesman when asked about Conoco's outlook.
Market sources said Conoco was looking for a local partner but the spokesman declined to comment on the matter.
That leaves the rest of the field to Polish state firms and small independents with a handful of wells.
And industry insiders say it will be at least 12 months before exploratory drilling gathers pace again even at state-run firms such as PGNiG and PKN Orlen as they, like their foreign peers, slash spending to ride out the low oil prices.
When drilling does pick up, the pace of activity could hinge on whether the government offers subsidies, the industry sources said.
At the start of Poland's hoped-for shale boom, Jakub Kostecki, a 38-year-old entrepreneur, set up his firm, New Gas Contracting, to provide support services to foreign majors clamouring to get in.
Now, he has folded his company and relocated to Denver, Colorado.
"Most of our customers left," said Kostecki of his business in Poland. In a sign of the decline, he said he is now placing Polish specialists with U.S. firms because there is no work for them at home.
The numbers illustrate the decline: shale gas licences in Poland have fallen by half in the last two years to 53.
Just 10 investors remain in the Polish Exploration and Production Industry Organization, a lobby group that had 23 members in 2013.
PKN Orlen, which holds nine shale gas permits, said that all operators had to be cautious in allocating money to shale gas because of trends in energy prices.
Investors will also be looking out for a report due from the Polish Geological Institute, probably by mid-year, on the most updated reserves estimates.
"If the estimates turn out lower then either some incentives will be needed or only PGNiG and PKN Orlen will remain," said a manager at a small shale company, referring to measures including state subsidies.
"Shale gas and energy security will still be our priority," Prime Minister Ewa Kopacz told a news conference this month, but it remains unclear if subsidies will be offered. (Additional reporting by Michael Kahn in Prague; editing by Christian Lowe and Jason Neely)