The trendy Chelsea office building that’s the business home of Martha Stewart is close to being sold for more than $900 million.

The Starrett-Lehigh Building at 601 W. 26th St. is in contract to RXR Realty for a price tag that would equate to more than $400 a square foot, sources tell The Post. At a jumbo 2.32 million square feet, the building is the 10th largest in Manhattan.

It comprises the entire block bounded by 26th and 27th streets and Eleventh and Twelfth avenues and overlooks the Hudson River.

Many of the tenants like Martha Stewart — which has 220,000 square feet and roof decks — are in the fashion biz. They include Polo Ralph Lauren, Hugo Boss and Tommy Hilfiger, which is the building’s largest with 315,000 square feet.

Neither Harmon nor colleague Adam Spies could be reached for comment on the pending Starrett-Lehigh deal and a spokesman for Scott Rechler’s RXR declined to comment.