relinquish control over (something) (to someone or something)
To forfeit, turn over, or yield control of something (to another person, group, organization, etc.). She refused to relinquish control over the company to someone who wasn't in the family. They were forced to relinquish control over the land to the government. They will now relinquish control over the senate following the results of the election.
relinquish something over someone
to release the hold on or control of someone. She refused to relinquish control over the operations of the front office. Mary was ordered to relinquish her hold over the children for a month each year.