John Legg, Scottish director of the sight-loss charity the RNIB, has resigned after 10 years.
His departure comes just a few weeks after the charity made the controversial decision to transfer Scottish workers to its partner charity, Action for Blind People, a move that was strongly opposed by the union Unison.
Third Sector was unable to contact Legg for comment on why he had left, but the Herald Scotland newspaper reported that he had opposed the transfer of staff to Action for Blind People.
A spokesman for the RNIB declined to comment on whether Legg had left because of a disagreement about the transfer, which took place on 1 September.
The spokesman said: "John Legg, RNIB Scotland director, has decided to leave the charity at the end of October 2015 to further develop his career outside of RNIB.
"John has led a strong team that has tripled RNIB Scotland’s reach, developed an array of award-winning services and set new benchmarks for service delivery and service-user engagement."
He also praised Legg’s contribution at a national level and said the charity wished him well in the future.
When the transfer of staff, which included a total of 438 staff from Scotland, Wales and Northern Ireland, and the RNIB helpdesk in England, was proposed in June, Simon Watson, national officer for the community and voluntary sector at Unison, accused RNIB of not "being straight" with employees over why the move was taking place.