Is the commission shared with your colleagues in co-op cases different each time depending on how the events of each case develops? Apart from gentleman agreement or oral agreement made each time, is there any advice to avoid any later dispute among colleagues?

Typically the listing agreement will spell out the cooperating commission to be offered through MLS on a blanket basis. This does not preclude negotiation for something different on a case by case basis.

In the US one of the main purposes of a Multiple Listing Service is to publish the cooperative compensation offered

Get any agreements in writing to avoid misunderstandings later.

It's amazing how often a lapse of memory occurs when there's money on the table. :rolleyes: