PARIS (Reuters) - The French Socialist Party plans to put its headquarters in Paris up for sale, the party said on Tuesday, as it tries to reinvent itself after a poor performance in elections earlier this year.  The disappointing performance in the presidential and parliamentary elections split the party, and it will struggle financially. The sale of the Paris mansion, acquired in 1980, will be used in part to cover the shortfall.  This new era that is ahead of us can also open up at a new place,  Jean-Francois Debat, the treasurer of the party told journalists. The number of Socialist seats in the 577-seat assembly plummeted from 280 in 2012 to just 29, the lowest in the post-war Fifth Republic. Parliament s lower house is now dominated by President Emmanuel Macron s centrist Republic on the Move party, which blew apart the traditional two-party system. The crisis facing the Socialists has its roots in a mid-term shift of former president Francois Hollande from being the self-proclaimed  enemy  of bankers and defender of workers to advocate of business-friendly reform. The move split the party, exposing a deep-seated rift between moderates and hard-left lawmakers. 