Royal Mail handed almost £6m to its new boss to buy him out of his contract, in a move which has been slammed as "obscene" by the postal workers' union.
Rico Back's contract as chief executive of Royal Mail owned GLS was terminated in exchange for €6.6m (£5.8m) and replaced with a new one.
This came just a few months before it was announced that he would replace Moya Greene as CEO of the whole Royal Mail group.
After Sky News reported the payment tonight, Communications Workers Union deputy general secretary Terry Pullinger said it was "not a good start" to Back's tenure.
"On a personal level I find these arrangements obscene and it will be interesting the first time Mr Back pleads poverty when we discuss reward for our members or request more investment in growth, clearly Royal Mail have," he said.
"It beggars belief that people should be surprised that we are calling for a new deal for workers, a fairer share for all and the re-nationalisation of Royal Mail, it is the people's service and not a cash cow for the few. Stories like these are unacceptable".
Royal Mail said that it had sought to replace the original contract in order to remove certain management control rights held by Back, including veto ability.
"The Board came to the conclusion that some of the provisions of the original contract were increasingly inappropriate and needed to be removed," the company said in a statement.
It added that as part of the contract buyout, Back's fixed pay was rebased downwards.