The Guardian newspaper will switch to tabloid format from early 2018, the newspaper's owner said, after deciding to outsource the printing of its two best-known titles in a bid to keep costs down.
Publisher Guardian Media Group (GMG) said it had agreed a contract with Trinity Mirror for it to print the Guardian and its Sunday stablemate The Observer from early 2018.
Both titles will move to tabloid formats then.
Reuters had reported in January that the newspaper was considering such a switch.
Outsourcing the printing of the newspapers will help the publisher to lower costs, and rivals' printers are better suited to publishing tabloids.
GMG opted for a deal with Trinity Mirror, which publishes the Daily Mirror, over News UK which is owned by Rupert Murdoch.
At the moment, GMG prints the Guardian and The Observer on special presses bought more than 11 years ago when it switched from a broadsheet to the mid-sized Berliner format.
But the publisher said last year it needed to make savings of 20% to stem underlying losses that widened to £62.6m for the year to April 3. It said it was aiming to break even in three years.
GMG said that the move would make a "significant contribution" to meeting its financial targets.
"This is an important step in our three-year transformation plan. More people are reading and supporting our journalism than ever before, but the print industry continues to evolve, and we must evolve with it," David Pemsel, chief executive, Guardian Media Group, said.
He said the switch would impact print site employees.
GMG is owned by The Scott Trust, created in 1936 to safeguard its flagship newspaper.
