Add property to keep released versions for dependencies

When I release a project with many modules with internal dependencies.
I would like those dependencies to keep the released version rather than the next development version.

ie: I only release some modules at a time (those that were changed only since last release).
So when my webapp is released, I want it to become SNAPSHOT again(as it is done already) but want the internal dependencies to keep the released version.
I want to update them manually whenever I change one.