In customer service industry one needs to be polite with the customer. While asking a person to wait for a while on a call what would be more appropriate - "May I put you on hold / place you on hold / place your call on hold for a minute?". Thanks

Mister Micawber wrote:

May I put you on hold -- most casual/familiar ...place you on hold -- medium ...place your call on hold -- most formal/polite

I agree. There is "May I" to consider as well. If you say "May I put you on hold" it sounds like you tried to be polite, but slightly miss the point, for example you lost your nerve. With "May I place you on hold", it has stress on "you", for example one wants to say "May I place your case", "May I place you with your request". "You" replaces something from the conversation. In "May I place your call on hold" you are concerned mostly with the call, the least of other two with the subject of the conversation.