The group is consulting with 33 staff on plans to close its printing site near Cardiff Docks.
Trinity Mirror wants to print the Western Mail in Watford and the South Wales Echo in Oxford, it is understood.
The company said the consultation process was ongoing.
The group previously blamed "declining print volumes and the relocation of a number of titles within our print network" for the proposed closure of the print works, which is responsible for a number of Trinity Mirror newspapers as well as other publications.
Trinity Mirror also owns Wales on Sunday, which is already printed in Birmingham, as well as the South Wales Evening Post and the Daily Post.
Meanwhile, BBC Wales understands the company is in talks to sell its Media Wales building in Cardiff city centre.
The company plans to remain as a tenant when the deal is completed.
Media Wales moved into the six storey purpose-built office block on Park Street in 2008.
Staff cuts mean its sales and editorial teams now only occupy one floor, while accountancy firm Deloitte has taken some of the vacant space.
Trinity Mirror declined to comment on the proposed sale of its Media Wales headquarters.
Newspaper publisher Trinity Mirror plans to print some of its Welsh titles in London and Oxford when it closes its presses in Cardiff, BBC Wales has learned.