The bodies have set up a Task Force and their immediate priority is to identify their requirements in terms of rail infrastructure and service improvements, and consider ways to secure investments.
Mae'r cyrff wedi sefydlu Grŵp Gorchwyl, a'r flaenoriaeth gyntaf yw nodi eu gofynion o ran gwella gwasanaethau a seilwaith rheilffyrdd, ac ystyried ffyrdd o sicrhau buddsoddiadau.