DETROIT— The new owners of the struggling Hotel Pontchartrain here said that they plan to make top-to-bottom renovations and affiliate it with the Hilton or Sheraton chains, according to a published report. Shubh Hotels Detroit LLC, a partnership based in Boca Raton, FL, purchased the Detroit hotel Tuesday for an undisclosed price, said Harris Mathis, the groups director of operations. The Pontchartrain opened in 1965. Its distinctive faceted facade gives each room a view of the Detroit River. However, it has struggled for years in a weak downtown hotel market. The hotel was previously owned by Irvine, TX-based Highgate Holdings Inc. It was recently returned to its creditor, GE Capital, and was to have been auctioned March 8. That auction has been canceled, according to auction service Tranzon Bippus of Three Rivers. The Pontchartrain has 384 rooms and 110 employees, said Ray Dias, the hotels general manager. It also has a bar, restaurant, banquet center and 168-space parking garage. The Shubh organization plans on keeping the Pontchartrain open while renovations are made a few floors at a time, Mathis said in a local report. He did not say how much money the new owners planned on investing in the makeover. “We plan to renovate the rooms, corridors, lobby, elevators, everything,” Sanjay Patel, another Shubh principal, said in the published report.