The team reached the deal with Horford just ahead of a deadline that would have opened the door for one of their stalwart players to become a restricted free agent next summer. Horford confirmed the terms in an e-mail to the Associated Press.
"I wanted to get it done for security and just to focus on the team this year," Horford wrote while en route to Cleveland, where the Hawks (3-0) face the Cavaliers on Tuesday.
The 24-year-old Horford was the No. 3 overall pick in 2007 from Florida, helping the Gators win consecutive national championships.
He quickly established himself as one of the team's most valuable players, even as an undersized center who had to outwork many of the bigger players he went against.
Horford finished second in the NBA rookie-of-the-year voting to Kevin Durant.
Duke's Kyle Singler was the leading vote-getter and only repeat selection for the AP preseason men's basketball All-America team, and North Carolina's Harrison Barnes became the first freshman to make the list since voting began before the 1986-87 season.
The team was chosen by the 65-member national media panel that selects the AP top 25 men's basketball poll.
Singler, the leader of the Blue Devils' run to a fourth national championship last season, was listed on 62 of 65 ballots. Barnes received the lowest vote total of the starters with 17.
Rios replaces Pavlik on Texas undercard
Oxnard lightweight Brandon Rios will fight an undercard bout Nov. 13 on the Manny Pacquiao-Antonio Margarito card at Cowboys Stadium in Arlington, Texas, promoter Bob Arum said.
Rios, whose opponent could be announced Tuesday, replaces former world middleweight champion Kelly Pavlik, who withdrew from the card Monday because of a training-camp rib injury.
Davey Lopes has informed the Philadelphia Phillies he won't return as first base coach, the team said.
Lopes spent the last four seasons with the Phillies, and played a significant role in the team's success in stealing bases. Under Lopes, the Phillies led the league in stolen-base percentage four seasons in a row.
Lopes was a four-time All-Star second baseman with the Dodgers during a 16-year career. He also managed the Milwaukee Brewers for two years and parts of another.
The struggling New Jersey Devils are going to be without high-scoring left wing Zach Parise for an undisclosed amount of time.
Parise will have exploratory arthroscopic knee surgery to determine what has been causing him problems all season.
Roger Federer easily won his opening match in his hometown tournament, beating Alexandr Dolgopolov, 6-4, 5-2, in the Swiss Indoors at Basel.