The start of the world's biggest technology show has been marred by a row over a lack of female speakers.
The top six speakers at the Consumer Electronics Show (CES), among them Intel chief executive Brian Krzanich and Ford's Jim Hackett, are all male for the second year in a row.
This has led to a backlash from campaigners who say it is symbolic of a lack of diversity in the tech industry.
CES, an enormous festival held each year in Las Vegas, is meant to be a showcase for the best of the technology industry and a glimpse of the inventions of tomorrow.
But after a year in which Silicon Valley was forced to confront a culture that is seen as male-dominated, the line-up has struck some critics as tone-deaf.
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.