The artist representation agreement is non-exclusive. This means you retain the copyright. You are also free to submit the music to any other library as long as it is also non-exclusive.
Please keep in mind, once your material is accepted to any non-exclusive library, it is highly discouraged to later sign an exclusive agreement with another library. Switching representation causes lots of management problems and usually leads to frustration for everybody involved, including the copyright holder, all the libraries and most importantly, the end user who purchases the sync licenses.