A group of female employees at Nike Inc. last year circulated an informal survey about alleged inappropriate behavior by men at the world’s largest sportswear maker, people familiar with the matter said, a move that preceded the ouster of two veteran executives last week.

The women were frustrated with what they saw as pay disparity and a gender imbalance at the highest ranks of Nike, the people said, amplified by the exit of several female senior operating executives last year.

The women were also concerned about allegations circulating internally of inappropriate workplace behavior by some men and drew up the survey to gather information about these issues, the people said.

The distribution of the survey came to the attention of longtime Nike Chief Executive Mark Parker in recent months and triggered a formal review of workplace behavior by an outside firm, the people said. The results of the survey couldn’t be learned.