A statement from Trinity Mirror said that a consultation had begun with 33 staff over the proposed closure of the site, which is based at Portmanmoor Road, Cardiff.
“This is a result of declining print volumes and the relocation of a number of titles within our print network,” said the statement.
The group prints most of South Wales’ newspapers, including the Western Mail, South Wales Echo, South Wales Evening Post and the Llanelli Star. It also prints a number of Tindle Newspapers’ titles and does contract work for universities.
It is currently unclear where the titles will be relocated to.
PrintWeek understands that union representatives are speaking to company bosses this afternoon.
The site currently runs a four-colour Goss Colorliner, which can run as two presses depending on pagination size, and two Goss J255 folders.
Cardiff production manager Owen Beesley said: “Obviously at present we have been informed that the site looks like it will close at the end of the year, whether that will happen yet we don’t know, but it is looking likely.
“Newcastle closed at pretty much the same time last year in the same way that this one will close, because of fewer contracts. Location and logistics, which used to play a big part in where newspapers were printed, is much less important now when you're working out costs.”
Last year, Trinity Mirror’s Newcastle site closed, with 49 jobs placed under threat, and the company shut its Blantyre, Scotland operation in a cost-cutting exercise a number of months beforehand.
Trinity's other sites are at Birmingham, Cardonald (Glasgow), Oldham, Teeside and Watford.
“Everybody’s disappointed about Cardiff but it’s out of our hands. I’ve worked for Trinity since I was 17 and have enjoyed the years here but everything comes to an end,” added Beesley.
South Wales Echo former editor Alistair Milburn told BBC Radio Wales Good Evening Wales programme that the day would come “sooner rather than later” where the likes of the Western Mail won’t exist as a print product.
Earlier this year, Trinity Mirror launched The New Day, a new daily newspaper, and then subsequently withdrew it after just nine weeks in circulation.
