In one of the largest U.S. real estate deals in recent memory, a pair of Am Law 100 firms are advising on a proposed $1.1 billion sale of consumer electronics giant Sony’s U.S. headquarters to the Chetrit Group, a family-owned property management and development company.

The deal, which was announced earlier this month, is expected to close sometime in March. Sony issued a public statement that its main motivation for the unloading the building— located at 550 Madison Avenue in midtown Manhattan—was a desire to raise $770 million in cash to bolster its balance sheet. The remaining proceeds from the sale will be used to pay down Sony’s debt on the office tower.