The developer of the Ground Zero mosque is unloading a $65 million Flatiron District office building in an attempt to generate much-needed cash.

Sharif El-Gamal’s Soho Properties is selling a 12-story building at 31 W. 27th St.

Soho Properties bought the building in 2009 for $45.7 million and assumed the $39 million mortgage on it.

El-Gamal appears in serious need of cash, both for his Park 51 mosque and community center and to pay for repairs, back taxes, utility charges and other fees on buildings his companies own in Washington Heights.

His controversial plan to build the $100 million worship center on Park Place near Ground Zero has stalled. He owns only half the site and needs to buy the other half from Con Edison.

The utility and El-Gamal are currently in a legal battle over the asking price of $10.7 million and the $1.7 million in back rent Con Ed says the developer owes.