Staff in the Prudential's annuities department in Reading will from Wednesday not carry out work linked to the transfer of the jobs to Mumbai, Unite said in a statement.
97 percent of the Unite members voted for the industrial action, the union said.
A spokesman for Prudential said around 80 jobs were being transferred to Mumbai, but at least 30 UK employees had already found other roles in the company.
(Reporting by Carolyn Cohn; Editing by Alexander Smith)
