The body has been under pressure from the US government to change its operating procedures if it wants to continue. ICANN was created in 1998 to oversee the domain name system and operates under an agreement with the US Department of Commerce, which is due to expire on 30 September.
The reform blueprint calls for ICANN to reduce the number of board members from 18 to 15 and to replace elections for some board members with selections by a nominating committee.
"The vote was 18 to zero by the board - there wasn't any controversy," said ICANN president and chief executive Stuart Lynn. "The board feels very strongly that this is the right way to go. It is a major step forward," Lynn said.
"Everyone on the board feels very strongly that we need a geographically and culturally diverse ICANN."
ICANN would also seek to make its processes and policies more open to public discussion.
Lynn stressed that ICANN was not reforming itself simply to appease Washington, though the reform blueprint does call for more active governmental participation in ICANN.
The proposed reforms would include dismantling the Protocol Supporting Organisation and replacing it with a Technical Advisory Committee. Also ICANN will establish a Country-code Names Supporting Organisation. The name of the Domain Name Supporting Organisation would be changed to the Generic Name Supporting Organisation.
The new structure may take time to work. New board members will not be appointed until March or April next year, said ICANN.