BERLIN (Reuters) - Chancellor Angela Merkel's conservatives want to revive a bilateral tax agreement with Switzerland in coalition talks with the Social Democrats, who blocked the proposed tax deal in the upper house last year. Markus Soeder, finance minister in the state of Bavaria, told journalists in Berlin the federal and state governments in Germany could get significant funds if the bilateral deal with Switzerland was ever approved. Soeder, one of the conservative Christian Democrats' leaders in the coalition talks, said he was in favor of tightening rules on tax evasion, in comments supported by another conservative negotiator, Norbert Barthle. The Christian Democrats and SPD are in talks on a right-left "grand coalition" government after Merkel's ruling conservatives fell short of an absolute majority in September's election. Merkel said the planned deal with Switzerland last year would have brought Germany tax revenues of 2 billion euros ($2.74 billion)or more. Most would have gone to Germany's 16 states. The SPD and the Greens, who control Germany's upper house of parliament, scuppered the deal, arguing it was too lenient as it would have protected the anonymity of German account holders while imposing a tax on their assets. The EU's six biggest countries agreed this year to increase cooperation to pile pressure on tax havens which want to protect bank secrecy. (Reporting by Matthias Sobolewski; writing by Erik Kirschbaum; editing by Andrew Roche)