(Adds comments from gas firm and analyst, more background)
                                 By Peter Laca
                                 BRATISLAVA, Aug 18 (Reuters) - Slovak Prime Minister Robert
Fico has stepped up his pressure on utilities over energy costs,
warning their western owners he may expropriate their property
if they seek to overcharge people, media reported on Monday.
                                 Fico's statement escalates his clash with western-run
utilities as he aims to prevent hikes in household energy bills
-- a key promise that helped him win a 2006 election.
                                 Analysts, however, said the cabinet was unlikely to seek
expropriation as it would be too costly for the state.
                                 "(The Constitution) says a thing can be expropriated in
public interest," Fico said in an interview for local news
agency SITA carried by the daily Hospodarske Noviny.
                                 "If they, and it's not just Enel but foreign owners of
energy monopolies (in general), continued in policy that is
basically against the interest of this state, its people, and
therefore against public interest, we will not be shy to use
even such extreme options in the future," Fico said.
                                 Fico's spokeswoman had no further immediate comment.
                                 Slovakia's main energy firms are run by foreign utilities
following extensive privatisation process by the previous
centre-right government earlier this decade.
                                 Leftist leader Fico has focused mainly on the dominant power
maker Slovenske Elektrarne and natural gas monopoly SPP in his
effort to make good on election promises.
                                 Slovenske Elektrarne is 66-percent owned by Italy's Enel
<ENEI.MI>, while SPP is run by Gaz de France <GSZ.PA> and
Germany's E.ON <EONGn.DE> through a combined 49-percent stake
and management rights.
                                 The main energy companies have said prices will have to
increase due to rising cost of oil on the world markets, but
Fico said utilities only want to boost their profits.
                                 "We will not abandon people, we will fight until the very
last option," the paper quoted Fico as saying.
                                 A Slovenske Elektrarne spokesman said the constitution
guarantees appropriate compensation if the state wanted to
interfere with property rights.
                                 SPP would not comment on the expropriation warning, but
added its prices reflect developments with commodity costs.
                                 Apart from the energy sector, Fico has also clashed with
other private businesses since taking power two years ago.
                                 The government has adopted a law banning private health
insurers from keeping profits, and he has threatened to punish 
retailers if the cabinet deemed their price hikes unjustified
after Slovakia adopts the euro in January 2009.
                                 Peter Golias, an analyst with the Bratislava-based
think-tank Ineko, said Fico's latest comments appeared to be
aimed at telling his voters he is protecting them against rising
electricity and natural gas prices.
                                 "Fico knows that expropriation would require compensation,
and the state would not be able to afford such a financial
burden," Golias said.
 (Editing by Louise Ireland)