challenger Gerhard Schroeder`s in opinin polls for most of the campaign but he mounted a strong comeback to turn it into the closest race since World War Two. More than 60 million Germans are eligible to vote for the two men vying to lead Europe`s economic powerhouse. Politicians and pollsters expect a high turnout, above 80 percent. Voters began casting ballots under partly cloudy skies at 8 a.m. Polling stations close at 6 p.m. The latest opinion polls that show Schroeder clinging to a small lead. Kohl`s defeat after 16 years in power seemed inevitable only six months ago when Schroeder won the SPD nomination and vowed to steer a course for the "new centre" of German politics. The "Schroeder effect" has weakened since August and Kohl`s conservative Christian Democratic Union (CDU) and its Bavarian sister party, Christian Social Union (CSU), have closed the gap to within the margin of error of many opinion polls. Because of Germany`s complex voting system the winner could be Kohl, Schroeder or Kohl`s loyal deputy Wolfgang Schaeuble. Schroeder had hoped to form a government with the left-wing, environmentalist Greens party. But the erosion of SPD support makes a grand coalition of SPD and CDU a likely option. Germany`s election laws add to the unpredictability of the race because small shifts in local voting patterns can have a decisive influence on the final result in Bonn. Under this system, no post-war chancellor has been voted out of office. Earlier switches of power came about through shifts in coalitions. There are 656 seats in parliament, half elected by direct votes for deputies from the 328 constituencies and half picked from party slates in the 16 federal states that voters choose with the second ballot they cast on Sunday. Thirty-three parties with 5,062 candidates ranging from neo-Nazis to anarchists have entered the field. The small parties could hold the balance of power. An SPD-Green government could be scuppered by the reform communist Party of Democratic Socialism. The PDS is battling the SPD in the former communist east. If it wins three direct seats in its Berlin stronghold it can get around the five percent hurlde and enter parliament. This would make an SPD-Green alliance impossible on current projections.