Sony Corp. has sold its iconic US headquarters building for $1.1 billion to the Chetrit Group.

The sale of the building, at 550 Madison Ave., with the Chippendale chair-like roof line, comes with a three-year lease-back provision — meaning Sony — and its Sony Music Entertainment, Sony/ATV Music Publishing and Sony Pictures Entertainment units — will remain in the building for up to 36 months, the company said in a statement last night.

Sony will realize a gain of $685 million on the sale, which will be recorded as operating income, the company said.

The deal is expected to close in March.

Eastdil Secured advised Sony on this transaction.

Sony, which has lost money in each of the past four years, is selling the Midtown building to strengthen its balance sheet and provide the cash for future growth — including possible acquisitions.