iOS Resize MKAnnotationView

[arnieterm]

Hi all
How can we resize the MKAnnotationView? I need to show a custom view that contains a heading label a rating UIView and a 2-3 line text with an image on its right.
I have created a nib with all the stuff in it and in the

- (MKAnnotationView *) mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>) annotation

I assign the view generated as a result from alloc/initWithNibName and assign to the leftCallOutView property of MKAnnotationView.
The problem is that the leftCallOutView's height is more than the default frame of MKAnnotationView.
So how can we resize the MKAnnotationView to hold the leftCallOutView entirely.
The leftCallOutView is hardly 60-70 pixel in height

Thanks
Arnieterm