Members of the National Union of Journalists and Broadcasting, Entertainment, Cinematograph and Theater Union approved job actions to protest the decision to cut 2,000 jobs over the next five years. While the company said the cutbacks -- dubbed "Delivering Quality First" by managers -- will be carried out mostly by attrition, 110 workers face layoffs.
The unions held a 24-hour walkout in February, and leaders say more may follow.
Michelle Stanistreet, general secretary of the NUJ, said the BBC has not agreed to a call for a moratorium on the cutbacks.
"The DQF plans remain on the table, regardless of the consequence for workload and stress levels," she said. "We know that the cuts are already having an impact on the quality of work. We know that it is leading to unacceptable workloads and stress."
Some live newscasts were cut back or canceled Thursday.
Union members said they would return to work during the stoppage if former South African President Nelson Mandela died, The Daily Telegraph reported. The 94-year-old has been hospitalized.