Periscope ad agency's parent company changed a rule forbidding employees from using "Black Lives Matter" in social media posts after 179 Minneapolis workers walked off the job on Thursday.

Employees said they wanted to use the term to show solidarity with Black and racial-justice protesters in the wake of the George Floyd killing, but were repeatedly told no by Wisconsin-based parent company, Quad.

After the walkout, Quad agreed to give Periscope editorial independence over its social media posts and promised to release employment data by race and sex. Leaders also said they would undergo diversity training and planned to increase the number of people of color hired throughout the company.

Quad CEO Joel Quadracci apologized to Periscope employees and clients in a statement. He said the company was "slow to communicate" its commitment to ending systemic racism.

"Our integrated marketing agency Periscope in Minneapolis has witnessed firsthand the nation's reawakening to persistent, systemic racism," he said. "In recent days, our Periscope colleagues have made it clear that we, as a company, failed to act with the urgency, transparency and sensitivity required on this important social issue, and we agree. Quad can and will do better."

Nathan Young, who moved from Seattle in March to join Periscope as group strategy director, said he is still shocked that Quadracci directly ordered him to delete the phrase "Black Lives Matter" from a Periscope statement addressing systemic racism.

For a month, he was told Quad first needed to review its policies.

"The fact that as a billionaire white CEO of a company, you literally told your Black employee — one who lives four blocks from where George Floyd was murdered — to delete the phrase 'Black Lives Matter' from a statement of support, is a shocking dereliction of duty as a leader," Young said. "The wound that created never fully healed."

Subsequent efforts to retweet supportive messages on Facebook or Twitter prompted Quad's legal staff to intervene.

On Wednesday, Young, Periscope's three other Black employees and one LGBT worker walked off the job in protest. On Thursday, the rest of the office walked out, too. Periscope has 16 people of color on its 179-member staff.

Young is one of two advertising leaders who rallied 600 Black advertising professionals to pen a letter outlining 12 actions agencies should take to help eradicate systemic racism in their organizations.

Chief Creative Officer Peter Nicholson said Quad's initial decisions were "particularly hurtful to our people of color and to all 179 of us because of the situation we were all experiencing" in the wake of Floyd's killing.

Nicholson said he was proud of the agency for banding together.

Periscope closed Thursday for "reflection and in solidarity with our colleagues," the agency said in a statement. "We believe the day is necessary for us to reaffirm our values and our commitment to real change — not only for ourselves but for our wider community."

Correction: Previous versions of this article misspelled the name of Quad CEO Joel Quadracci.