In an internal email to staff, the editor-in-chief of Reuters News, David Schlesinger, said having looked into areas of "natural overlap and duplication in coverage" between Thomson and Reuters the newly merged company had decided more than half of the cuts would be in Europe.
"After looking at both the unique content that each news operation produces as well as news that is duplicated, I believe that the combined size of the new Reuters News at the end of the year should be around 2,500 - significantly more than the 2,380 the old Reuters editorial ended 2007 with," he told staff in the memo, seen by MediaGuardian.co.uk.
"Unfortunately, the overlap we've found and our need to run the operation efficiently means that we will have to eliminate around 140 jobs worldwide by the end of the year," he added.
"More than half the cuts will occur in Europe, the area of most duplication; the rest will be scattered. Thomson Financial News will be totally absorbed into Reuters News by end of 2008, and sooner if possible.
Schlesinger said cuts in the news department would be offset by "hiring into new projects".
"I anticipate that over the coming months we will add some 50 new jobs in key areas that are central to my strategy of making us the best news service for the 21st century," he added.
Thomson Reuters told staff last week that it would be creating new web video roles and offering its readers more commentary and analysis.
Schlesinger said the company, which combines the London-based Reuters with Canada's Thomson, will begin consultation with affected unions, works councils and staff "immediately". He did not make clear whether any redundancies would be on a voluntary or compulsory basis.
At the news wire operations of both Thomson and Reuters, union members said they are ready to take industrial action over the way managers are expected to go about the job cuts.
Staff added that the tone from management briefings so far suggests employees will be forced out of their jobs because Thomson Reuters is expected to opt for compulsory redundancies to cut out overlap.
National Union of Journalists officials said managers have so far refused to commit to using voluntary redundancies and as a result staff have already voted to hold a strike ballot.
The journalist job losses follow last week's news of cuts elsewhere within Thomson Reuters, with up to 700 posts to be axed across sales and technical support.
Staff at the company were told last week that up to 650 posts will go from its content, technology and operations division, with around 250 redundancies.
In addition, 45 jobs will go from sales teams in its central Europe, Middle East and Africa division out of a total of 1,305 posts.
Employees have been nervously awaiting job losses ever since Thomson's takeover of Reuters was agreed a year ago, with both groups flagging up opportunities to cut costs in the various parts of the two businesses that overlap.
A spokesman for the company declined to comment.
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