The company has not revealed the number of staff affected, but has confirmed reception staff in Widnes and advertising staff in Caernarfon are at risk of redundancy.
The announcement was made to staff on Friday by Carl Wood, above, managing director of Trinity Mirror North West, in an email which has been seen by HTFP.
He wrote: “As you know, throughout Trinity Mirror we are continually seeking efficiencies based on better use of technology This is part of a strategy to invest in advertising and editorial, rather than bricks and mortar, where possible.
“The strategy also reflects a wish for staff to be out and about meeting people in our communities rather than being desk-bound. The technology we have now facilitates this.
“Sadly, the closure of these office means our colleagues on reception in Widnes and in private advertising in Caernarfon are at risk of redundancy and we have today entered a 30-day period of consultation with them.
“We are also speaking to editorial and advertising staff about how things will change from the end of June, and how we can help them make the transition.”
Trinity Mirror North West editor-in-chief Alastair Machray said in a company statement: “These are two very important parts of our portfolio and we remain absolutely committed to the areas and to our brands there.
“While these are well-established offices, I would much rather be investing in our journalists, rather than in traditional and out-moded office space.
“It is our intention to develop our businesses out of our major centres. We remain completely committed to these marketplaces and to our brands there.”
However the National Union of Journalists has expressed “deep concern” about the proposal to close the Caernarfon office and is to organise a protest rally against the move on Saturday 11 April.
Paul Scott, chair of the union’s North Wales branch and National Executive Council member for Wales said: “Caernarfon is the county town of Gwynedd, has a magistrates and crown court and is home to the headquarters and debating chamber of the local authority as well as the North West Wales coroner.
“To withdraw from Caernarfon is to withdraw from the principle of localism itself and Trinity Mirror’s decision to close its office suggests a dwindling commitment to local media and bodes poorly as far as the future of its regional news operations is concerned.
“We are seeking to resist this closure in order to maintain a meaningful journalistic presence in Caernarfon.
“As a journalist who has worked for the Caernarfon and Denbigh Herald, Daily Post, Holyhead and Anglesey Mail and Bangor and Anglesey Mail, I know the high regard that these newspaper titles are held in.”
Paul said journalists working at the existing office had been they will be required to either work from home or relocate to Llandudno Junction.
He added: “While some of our members believe they will be able to adapt to these changes, others are unable to provide a suitable working environment at home or travel to Llandudno Junction where shifts range from 6am to 10pm.”