A council which was threatened with disciplinary action from the Museums Association for selling off a Lowry painting, has resigned from the body.
Bury Council sold A Riverbank for £1.25m to balance its books.
Chief executive Mark Sanders said the MA's president caused "resentment" by accusing the Greater Manchester council of "cultural vandalism".
The MA may still decide to retrospectively expel the council, despite its resignation.
The Museums, Libraries and Archives Council is also yet to decide whether Bury will lose its museum accreditation.
The loss of status would affect the grants the authority is eligible for.
A Riverbank sold for more than twice the expected price when it went under the hammer at Christie's a week ago. It cost the council £175 in 1951.
In a letter to the MA's president, Charles Saumarez Smith, Mr Sanders said that he felt the result of its future tribunal hearing was "pre-ordained".
He added: "Bury stands accused of 'arbitrary cultural vandalism'.
"I have no doubt that this had the ring of a good media sound-bite during your annual conference week, but I have to tell you that it was the cause of some resentment among the members of this council.
"In view of this situation, please consider this letter as the formal resignation of Bury MBC from the Museums Association."
Caitlin Griffiths, MA's advisor on professional issues, said the Lowry sale represented a "dark day" for museums.
"We can only hope that the MLA takes swift action to deter any other local authorities from doing the same thing, and that what has happened at Bury is a deplorable one-off," she said.
"As a result of the sale the MA will now proceed with disciplinary proceedings against Bury, the disciplinary panel will meet in early December to deal with this matter."