The union that represents staff members at the Boston Globe has taken the unusual step of placing an ad in a rival newspaper that blasts the Globe for outsourcing a number of jobs to India.

The ad, which ran Tuesday in the Boston Herald and was placed by the Boston Newspaper Guild, called the Globe’s decision to outsource advertising and circulation back office jobs “an egregious mistake.”

It also stated that the move could put Globe readers in danger of identity theft by “putting customers’ most vital information at risk.”

The Guild attempted to place the ad in the Boston Globe itself but it was rejected by the paper. “We didn’t run the ad because we believe it contained information that was inaccurate,” said a Boston Globe spokesman.

The spokesman said the paper chose to outsource the positions to save money.

Boston Globe corporate parent The New York Times Co. is outsourcing about 40 jobs at the Globe to Infosys Technologies, which will perform the work at a location in the Indian tech hub of Bangalore.

In response, the union ad reminded readers that the paper is “the Boston Globe, Not the Bangalore Globe.”