A woman who dated Uber CEO Travis Kalanick for three years, Gabi Holzwarth, says she was with Mr. Kalanick when he and a team of five Uber employees visited an escort-karaoke bar in Seoul in mid-2014. At the bar, women sat in a circle, identified by numbered tags. Four male Uber managers picked women out of the group, calling out their numbers, and sat with them, she says. About an hour later, she and Mr. Kalanick left.

A year later, a female Uber marketing manager who was in the group told Uber’s HR chief that the outing had made her uncomfortable, according to Ms. Holzwarth, who says she spoke to Mr. Kalanick about the complaint. Ms. Holzwarth also discussed the matter with the female Uber manager via instant message, which The Information has viewed.