Wall Street’s Morgan Stanley is expanding, sources tell The Post.

The financial firm run by James Gorman has expanded its lease at One New York Plaza by nearly 90,000 feet to total 1.3 million square feet.

Sources said the global firm took at least two floors totaling 88,699 square feet in the 2.581 million-square-foot tower.

The deal is good news for downtown, which has lagged in leasing as Hudson Yards and the West Side have snagged major tenants.

The 50-story building is owned by Brookfield, which recapitalized it at the end of 2016 for $1.395 billion. The white tower sits along the East River on the block bounded by Water, South Park and Broad streets.

In April 2012, Morgan Stanley expanded from over 800,000 square feet to 1.2 million square feet, as previously reported by The Post.

Other tenants include the law firm Fried Frank, which is the second-largest tenant with nearly 425,000 square feet and represented Morgan Stanley in the deal, sources told The Post, as did JLL brokers Peter Riguardi and Ken Siegel.

“There’s been a great relationship between Brookfield and Morgan Stanley and Brookfield has tried to accommodate Morgan Stanley’s expansion needs,” said attorney Jonathan Mechanic of Fried Frank, declining to discuss any aspects of the deal.

Sources said Brookfield was represented in-house by Jerry Larkin and Mikael Nahmias.

The other parties declined to comment or did not respond prior to press time.