The government is planning to block or hold up foreign takeovers of British energy companies in retaliation for Europe's failure to open up gas and electricity markets.  Among the first casualties could be the pounds 10bn takeover of PowerGen by E.ON, the German multi-utility, which the government will refer to the European Union competition authorities for investigation.  Electricite de France, the state-owned group which already owns London Electricity and the supply business of South West Electricity, would face a similar block or even veto if it makes its long-expected bid for electricity supplier Seeboard. Senior government officials said yesterday: "We are looking at ways of holding up European forays into the UK market. It may not be possible but, at the very least, we would force Brussels to intervene and impose an investigation on competition grounds, holding up the process."  This emerged as the European commission referred France to the European court of justice for failing to legally open up its gas market to com petition in line with a 1998 directive which requires 20% of that business to be liberalised.  Ministers' outrage at the ease with which big French and German players can buy into Britain's energy sector while there is no reciprocity in their own markets has risen since the failure of the March Stockholm summit to bring further deregulation.  France and Germany, which fell out at the Nice summit over EU institutional reform, combined to block progress on a new directive that would see Europe's market wholly competitive by 2005 at the latest.  Many leading UK groups, including Centrica, the dominant player, have become increasingly exasperated and frustrated at their exclusion from an EU market worth billions of pounds potentially.  Reflecting this, Peter Hain, trade and industry minister, said: "We want to see rapid liberalisation of the energy market in Europe and so do the vast majority of EU members . . .We are pressing the commission to bring forward this new directive."  Welcoming yesterday's "encouraging decisive action", he said: "We feel especially aggrieved when EdF is pursuing takeover negotiations with British companies, including Seeboard, but our own companies are blocked from reciprocal ventures."  Whitehall sources indicated that the new directive should be reactivated by the Belgians who take over the EU presidency on July 1 but no genuine movement is expected until after next year's French presidential election.  Even then, it is thought that the Germans, whose utilities enjoy substantial political support, are the most reluctant to see full-scale competition.  EdF, which paid pounds 2.4bn for its two UK electricity businesses, also owns two British power stations. It claims to have just 5% of the generation market and, with 3m domestic customers, to be the fifth largest in energy supply.  Sources refused to comment on any move for Seeboard which is owned by US group AEP which would want pounds 1.5bn for the business. But they made no secret of the French group's interest in acquiring Seeboard's 2m customers to give it critical mass in the UK.  Mr Hain yesterday approved pounds 25m in state aid to four British pits under a scheme to help the coal industry through short-term energy market problems and low world prices. Classification Language: ENGLISH Subject: TAKEOVERS (90%); EUROPEAN UNION (90%); EUROPEAN UNION INSTITUTIONS (90%); DEREGULATION (90%); ENERGY & UTILITY DEREGULATION (89%); FRENCH PRESIDENTS (78%); INTERNATIONAL LAW (78%); INTERNATIONAL ECONOMIC ORGANIZATIONS (76%); VETO (76%); ELECTIONS (73%); CAMPAIGNS & ELECTIONS (73%); INTERNATIONAL COURTS & TRIBUNALS (71%); EUROPEAN UNION COURTS (71%); EU PRESIDENCY (71%); COMMERCE DEPARTMENTS (68%); PETITIONS (67%); HEADS OF GOVERNMENT ELECTIONS (60%) Company: CENTRICA PLC (90%); ELECTRICITE DE FRANCE SA (EDF) (90%); E.ON SE (58%); CENTRICA PLC (90%); ELECTRICITE DE FRANCE SA (EDF) (90%); E.ON SE (58%); EUROPEAN UNION (57%); EUROPEAN UNION (57%); EUROPEAN COURT OF JUSTICE (56%); EUROPEAN COMMISSION (56%); EUROPEAN COMMISSION (56%); EUROPEAN COURT OF JUSTICE (56%) Organization: EUROPEAN UNION (57%); EUROPEAN UNION (57%); EUROPEAN COURT OF JUSTICE (56%); EUROPEAN COMMISSION (56%); EUROPEAN COMMISSION (56%); EUROPEAN COURT OF JUSTICE (56%); EUROPEAN UNION (57%); EUROPEAN UNION (57%); EUROPEAN COURT OF JUSTICE (56%); EUROPEAN COMMISSION (56%); EUROPEAN COMMISSION (56%); EUROPEAN COURT OF JUSTICE (56%) Ticker: CNA (LSE) (90%); EDF (PAR) (90%); EOAN (FRA) (58%); EOAN (BIT) (58%); CNA (LSE) (90%); EDF (PAR) (90%); EOAN (FRA) (58%); EOAN (BIT) (58%) Industry: ELECTRIC POWER INDUSTRY (90%); NATURAL GAS & ELECTRIC UTILITIES (90%); ELECTRIC POWER PLANTS (90%); ELECTRICITY TRANSMISSION & DISTRIBUTION (90%); ELECTRICITY MARKETS (89%); ENERGY & UTILITY TRADE (89%); ENERGY & UTILITY DEREGULATION (89%); ENERGY & UTILITY REGULATION & POLICY (78%); FUEL MARKETS (78%); UTILITIES INDUSTRY (78%); OIL & GAS INDUSTRY (78%) Geographic: LONDON, ENGLAND (79%); BRUSSELS, BELGIUM (78%); EUROPE (95%); FRANCE (94%); UNITED KINGDOM (94%); GERMANY (94%); EUROPEAN UNION MEMBER STATES (94%); BELGIUM (92%)