Twitter founder and Executive Chairman Jack Dorsey said on Tuesday that he trimmed his role at the microblogging service months ago as he devoted the majority of his time to Square, the payment start-up where he is chief executive.

Dorsey transferred all of his employee supervision to Twitter Chief Executive Dick Costolo in January as part of a pre-arranged transition process, Dorsey disclosed on his Tumblr blog.

"We haven't talked about this publicly because it's not what people using Twitter every day care about," Dorsey wrote.

Dorsey took to his personal blog to clarify his role at Twitter, the messaging service he invented in 2006, after The New York Times reported he had taken on a diminished role at the company after employees complained that he was "difficult to work with."

Dorsey was previously Twitter's CEO until 2008, when he was pushed out by Twitter co-founder Evan Williams. He launched Square that year.

Dorsey returned to his current role at Twitter in March 2011. He caused a stir within Silicon Valley last November when he said at a conference that he worked 8 hours at each company -- totaling 16 hours every day -- by being "very disciplined."