Apple CEO Tim Cook says he's proud to be gay.

The public declaration, in an essay written for Bloomberg Businessweek, makes Cook the highest-profile business CEO to "come out".

He said that while he never denied his sexuality, he never publicly acknowledged it, either. The chief executive said that for years he's been open with many people about his sexual orientation and that plenty of his Apple colleagues know he is gay.

Cook wrote in the column published on Thursday that it wasn't an easy choice to publicly disclose that he is gay, but he feels the acknowledgment can potentially help others.

"I've come to realize that my desire for personal privacy has been holding me back from doing something more important," he wrote.

Cook added that he considers "being gay among the greatest gifts God has given me."

He said he's been lucky to work for a company that "loves creativity and innovation and knows it can only flourish when you embrace people's differences."

Cook said he will continue to focus on being the best CEO he can be and will still call for equality for all people.