Germany\'s Free Democratic Party (FDP) leader Philipp Roesler offered to step down from the post on Monday, after his party saw the worst result in its 65-year history and crashed out of parliament in Sunday\'s election. As German Chancellor Angela Merkel\'s current junior coalition partner, the pro-business FDP failed to retain seats in the parliament with a disappointing result of 4.8 percent, falling short of the 5-percent minimum support to enter into the parliament, official provisional result showed early Monday morning. The FDP won a record 14.6 percent in the 2009 election and formed a coalition government with Merkel\'s conservative Christian Democrats (CDU). Roesler served as economy minister and deputy chancellor in the coalition government. Merkel\'s CDU and their Bavarian sister party the Christian Social Union (CSU) proved to be the biggest winner with 41.5 percent of votes in the federal election, the official provisional result showed. Without a majority of the parliament seats, CDU/CSU union has to find a partner to form a coalition in order to rule the Europe\'s largest economy for the next four years. A grand coalition with the center-left Social Democrats (SPD) as in Merkel\'s 2005-2009 first term seemed probable. Up to weeks of horse trading is expected for forming a grand coalition. \"We will discuss the issue in committees tomorrow,\" said Merkel on Sunday night.