A judge on Thursday upheld his ruling allowing the Barnes Foundation to move its multibillion-dollar art collection from the suburbs to Philadelphia, rejecting claims that new evidence should force a reconsideration of his hotly contested decision.

The opinion by Montgomery County Orphans Court Judge Stanley Ott seemed to eliminate any doubt about the planned May opening of the institution's new downtown home, which has been under construction for nearly two years.

Foundation President Derek Gillman praised the "clarity and thoroughness" of Ott's decision. But opponents of the relocation, known as the Friends of the Barnes, vowed to appeal. They said Ott's ruling left many issues unexamined.

Barnes officials are moving the collection, which includes dozens of paintings by Renoir, Cezanne, Matisse and Picasso, because they say the foundation is not financially viable at its original home in Lower Merion, about five miles from Philadelphia.

The relocation required Ott's approval since it breaks the trust created by the institution's late founder, eccentric pharmaceutical magnate Albert Barnes, who had ordered that the art never be moved. Ott granted permission in 2004.

The Friends have been fighting the decision for years, and Ott dismissed their most recent petition on Thursday. The group had contended that the 2009 documentary "The Art of Steal," which recounts the lengthy and bitter Barnes saga, contained information he lacked when he approved the relocation.

The Friends argued that then-Attorney General Mike Fisher, whose office had oversight of charitable trusts, made statements in the film that show he improperly acted as a "cheerleader" for the Barnes move when he should have been neutral.

Yet Ott ruled that the Friends "offered no case or other authority in support of this theory of mandatory impartiality."

The state attorney general's office had argued that Fisher was obligated to act in the public's best interest, which in this case meant saving the Barnes from financial ruin.

"As we said from the beginning, the Office of the Attorney General has always acted appropriately in this case and we're pleased that the court agrees," agency spokesman Nils Frederiksen told The Associated Press on Thursday.

Ott also reiterated his previous finding that the Friends, a citizens group that includes many neighbors of the Lower Merion gallery, lacked legal standing to block the relocation.