The Newspaper Guild of New York said the one-day action was taken by more than 350 editorial employees, who have been working without a contract for nearly two years.
The union said Reuters became the first major news organization to try to cover Wall Street from India last year when editorial managers started replacing their work force in the United States and London with "cheaper, far less experienced journalists in Bangalore."
Reuters' global cost-cutting program seeks to cut 3,000 jobs over three years and is now in its final year, the guild said.
Reuters Chief Executive Tom Glocer has said the company's Bangalore center eventually will employ 1,200 to 1,500 workers, according to the union. The guild has been told at least 50 of those jobs will be editorial.
Reuters is also proposing to consolidate its London and Washington photo-editing desks in Singapore, where wages are also lower.
Betty Wong, managing editor for Reuters America, said in a prepared statement: "Our Bangalore operation is meeting the company's high expectations. Reuters employees there are contributing to the quality and reliability of our products that Reuters customers have come to expect. Reuters is committed to achieving a fair and reasonable collective bargaining agreement with the Guild."
The guild, Local 31003 of the Communications Workers of America, represents nearly 500 print, television, and still-picture journalists, technicians, and other employees at Reuters America.
Earlier Thursday, Reuters said revenue from sales of its news terminals will continue to decline in the first three months of 2005, but at a lower rate than a year earlier.
Reuters' American depositary receipts rose 65 cents, or 1.5 percent, to close at $44.17 on the Nasdaq Stock Market.
By: (AP) Reuters Group PLC's U.S. journalists withheld their bylines today to protest demands for concessions in contract talks as well as management moves to export editorial jobs to low-wage countries.