Denver’s historic Esquire Theatre is for sale, despite a lengthy renovation less than a year ago by its national theater-chain operators, who have not paid rent since April. Commercial real estate firm Unique Properties this week advertised the building for $3.3 million, describing it as “a generational asset.” The building is owned by a family LLC known as Downing Street and leased by Landmark Theatres, which also operates the Mayan, Chez Artiste and Landmark Greenwood Village theaters in the metro area. “Like many tenants in town, they have not paid rent since April and that’s the reason why the family decided to put it on the market,” said Tim Finholm, executive vice president at Unique Properties.