San Antonio Spurs assistant Brett Brown has agreed to become the new head coach of the Philadelphia 76ers sources tell ESPN. Brown will sign a four-year contract to coach the Sixers according to which reported the agreement earlier. The 52-year-old Brown has been an assistant under Spurs coach Gregg Popovich for the past seven seasons and previously served as San Antonio's player-development coach. He also has international coaching experience guiding Australia to a seventh-place finish at the 2012 Summer Olympics in London. Brown becomes the second Spurs assistant to land a head-coaching job this offseason joining Mike Budenholzer (Hawks). Brown replaces Doug Collins who was not retained after three seasons as the 76ers' coach.