A major league source told ESPNChicago.com that Ramirez's contract is worth $36 million guaranteed with a mutual option for a fourth year.
Ramirez played the last eight-plus seasons with the Cubs. He hit .306 with 26 home runs and 93 RBIs and won the Silver Slugger award as the top offensive third baseman in 2011.
Kinzer said Ramirez expects the Brewers to be a contender next season, a critical factor in his decision.
"That was one of his criteria," Kinzer said. "There were about four teams that he liked that were contenders, and Milwaukee was at the top of his list."
Kinzer said Ramirez also likes the idea of playing indoors at Miller Park early in the season.
Ramirez is a Type B free agent, which means the Cubs receive a draft pick between the first and second rounds of the 2012 draft.
They receive the draft pick because they offered to go to arbitration with Ramirez, who declined.
Ramirez also declined a $16 million mutual option for the 2012 season. By offering to pick up the option, the Cubs saved themselves a $2 million buyout.
Ramirez had wanted a multiyear deal, and he didn't want to be part of a rebuilding project with the Cubs.
Milwaukee began last season with Casey McGehee as its regular third baseman, but McGehee's performance slipped after his breakout 2010 season. Jerry Hairston Jr., acquired in a midseason trade with the Washington Nationals, took over at third base for the Brewers late in the season.
Bringing back Hairston was no longer an option for the Brewers after he signed a $6 million, two-year deal with the Los Angeles Dodgers.
Late on Monday, the Brewers traded McGehee to Pittsburgh for right-handed reliever Jose Veras, who went 2-4 with a 3.80 ERA and one save in a career-high 79 appearances last season.
The Brewers also finalized their one-year contract with free agent shortstop Alex Gonzalez, a deal that includes an option for 2013 that could become guaranteed.
"Alex brings to our ballclub a veteran presence who has experienced winning in the postseason," Brewers general manager Doug Melvin said in a statement. "He is a plus defender who will be a welcome addition to our infield."
The 34-year-old Gonzalez batted .241 with 15 home runs and 56 RBIs in 149 games with Atlanta last season.
He made 146 starts at shortstop and had a .981 fielding percentage, which ranked third in the NL and fifth in the Major Leagues at his position.
Gonzalez is expected to replace last year's regular shortstop, Yuniesky Betancourt, who is a free agent.
The Brewers also agreed to a $700,000, one-year contract with catcher George Kottaras, avoiding arbitration, and to minor league deals with catcher Mike Rivera and first baseman Travis Ishikawa. They will report to major league spring training.
Bruce Levine covers baseball for ESPNChicago.com and ESPN 1000. Information from The Associated Press was used in this report.