The last rounds of redundancies at the company also affected staff that provided support to upper management, according to Minna Hirvonen, who's Stockmann's development manager and union shop steward.
She said that Stockmann workers need a period of calm after years of layoffs, outsourcing and deterioration of working conditions.
"The straw that broke the camel's back was on Wednesday, when the company announced plans that its IT-services were going to be outsourced," Hirvonen told Yle.
"All of the senior officials at the company want things to go well for Stockmann, but now measures need to be taken so that staff can carry on," Hirvonen said.
She said that about 100 executives and upper managers took part in the half-hour walkout.
Outsourcing nearly half of IT-services
On Wednesday, Stockmann announced that it had signed a deal with the India-based, multinational IT-services, outsourcing and consulting firm Tech Mahindra.
The company said it would shift some 33 of its IT-services workers to Tech Mahindra, leaving a remaining 40 workers to continue at Stockmann.
Last summer Stockmann cut the jobs of some 300 employees, which also affected internal service departments.
Stockmann's Human Resources Director Mikko Huttunen told Yle that he understands the worries of its workers.
Huttunen said that the company is engaging in discussions with executives about how to improve well-being and openness at that company.
"We have received the message that more forceful action in required," Huttunen said. "It's also what we strive for as an employer."