Manager Ozzie Guillen praised Buehrle over and over at baseball's winter meetings. They were together on the Chicago White Sox this season, and Guillen was eager to have the left-hander on his side next year.
"This kid is special," Guillen said. "He pitched in the big scenarios, big moments, very tough city to pitch. When people love you in Chicago, that means something."
Buehrle's deal is subject to a physical, which the sides were arranging.
The 32-year-old Buehrle has been one of the majors' most durable and effective pitchers for more than a decade. He has reached double figures in victories and thrown over 200 innings in each of the last 11 seasons, all with the White Sox.
Buehrle was 13-9 with a 3.59 ERA this year and won his third straight Gold Glove.
Buehrle is among the fastest workers in the big leagues. It works for him -- he's thrown two no-hitters while going 161-119 in the majors, including a perfect game against Tampa Bay in 2009.
A workhorse for the White Sox, he helped them win the 2005 World Series when he even made a relief appearance. Chicago offered him salary arbitration last month, but he decided to find a new home after a visit to Miami, where the Marlins will move into a new ballpark next season.
"Him moving from the American League to the National League, it's a big step for us," Guillen said.
"I think he's comfortable because I know what I'm going to get from him, and he knows what's going to come from us, and I think that helps," he said.
White Sox GM Kenny Williams was disappointed to lose Buehrle, but wished him well.
"Like I said, he will be missed," Williams told ESPNChicago.com. "I just told the Marlins owner he has one great pitcher but a better person. I'm happy for (Buehrle) but we have to move forward. I wish he and the Marlins well."
Hanley Ramirez's representative talked to the Marlins on Wednesday and asked for a restructured deal after the shortstop was asked to move to third base with the signing of Jose Reyes. The Marlins, upset with this, now are looking to trade Ramirez, the sources said.
However, two high-ranking Marlins officials denied that the Marlins were looking to trade Ramirez.
"We're not trading Hanley," one team official told Stark. "Everything is fine. We're not mad at him, and we're not trading him."
Ramirez tried to shoot down speculation of a possible trade or refusal to switch positions.
"Crazy stuff going around," he wrote on Twitter. "Im just relaxing with my family and getting mentally and physically strong and ready for next season."
"Of the top guys out there, we signed (closer Heath) Bell, we signed Buehrle and we signed Reyes," Guillen said. "That means we're showing people that they want to play for us, and for me."
One source said the Marlins told Pujols' camp if the team reached a deal Wednesday with one of their pitching targets, it would end their pursuit of Pujols. With Buehrle agreeing, Miami's 10-year offer to Pujols, that sources say would pay him more than $200 million and include provisions that would link Pujols to the Marlins beyond his playing career, was pulled off the table.
Information from ESPN The Magazine's Buster Olney, ESPN.com's Jayson Stark, ESPN.com's Jerry Crasnick and The Associated Press contributed to this report.