The Consumer Technology Association has sought to deflect criticism, pointing to the number of female speakers at lower-level talks, and saying there is "a limited pool when it comes to women in these positions".
But over the weekend the organisation promised to do more next year.
In a letter to Gina Glantz, the head of Gender Avenger, an organisation that campaigns for more women in speaking roles, the CTA said it would "redouble our efforts to expand women's voices throughout the conference and as featured speakers".
Many Silicon Valley companies champion equality but have been accused of failing to follow through.
A row erupted last year when Google fired an employee after he distributed a memo criticising diversity efforts at the company. A number of prominent male investors have been forced to step down from their roles after allegations of harassment emerged.