In preference to somebody/something
Definition 1 of 1
Pro Tip 1/3Choices Matter
The phrase emphasizes a deliberate choice between options based on preference. 
He opted for early retirement in preference to continuing his stressful career.
Pro Tip 2/3Subtle Preference
Use it to express a subtle or polite preference without strong criticism of the other options. 
In preference to driving, she takes the train for its comfort.
Pro Tip 3/3Consider Context
The context can be personal taste, practical reasons, health, ethics, etc. 
He chose the job in Berlin in preference to the one in London due to family ties.