The connecting element (3) is provided with a U-shaped configuration with a free arm (3a) and another free arm (3b). The former free arm is substantially extended perpendicularly to the center arm (3c). A locking projection (3h) is arranged in the region of the center arm. Independent claims are also included for the following: (1) a connection arrangement; and (2) a method for connecting a profile part (1), particularly a frame profile for a window or a door, with another profile part, particularly an extension profile.
