The Australian international has been lured from the J-League's Shimizu S-Pulse for as much as a reported €4 million by the reigning UAE Pro League champions
The 28-year-old striker has been a driving force in S-Pulse's attack this season, with six goals from 23 appearances. Brosque has also earned a regular spot in Holger Osieck's Australia squad, although the Socceroos have struggled in Group B of the AFC's final round of World Cup qualifying with two points from three matches.
Al Ain announced the two-year signing on their website, complete with a picture showing Brosque holding up his new club's shirt. He will wear No. 32, pending his registration with the league.
S-Pulse general manager Yasushi Hara declined to comment to media on Wednesday, and as of Thursday morning the club had made no official announcement.
Despite the cash infusion, the transfer will leave S-Pulse without one of their top attackers as they head into the final two months of the J-League season as well as the second leg of the J-League Cup in two weeks.
Brosque is reportedly set to arrive in Japan on Thursday in order to finalise his transfer paperwork before returning to the UAE this weekend.