When the bell rang to start NFL free agency Tuesday, the Falcons didn’t rush to throw some of Arthur Blank’s cash around.

They waited.

They watched.

Then they pounced.

On Thursday, the Falcons struck a modest three-year, $12 million deal with former St. Louis Rams running back Steven Jackson to replace the highly productive Michael Turner, who was released March 1.

“Steven has been on our mind since the days leading into free agency,” Falcons general manager Thomas Dimitroff said. “We kept a nice cool, calm, collected approach to this.”

The free-agent market for running backs settled after Detroit signed Reggie Bush (four years for $16 million), Tennessee signed Shonn Greene (three years, $10 million) and Arizona signed Rashard Mendenhall (one year, $2.5 million).

“We had a good feeling that we were going to have an opportunity to consummate a deal,” Dimitroff said. “It was really easy navigating Steven’s agent, Eugene Parker, who was mindful of the approach we were taking in negotiations.”

Jackson, 6-foot-2, 240 pounds, voided the last year of his contract with the Rams in order to become a free agent. His deal with the Falcons has $4 million guaranteed.

Jackson, who will turn 30 in July, is considered a better fit for offensive coordinator Dirk Koetter’s offense because he’s a better pass catcher than Turner, who was showing signs of slowing down and failed a physical.

Jackson has rushed for 10,135 yards and 56 touchdowns since being taken in the first round (24th overall) of the 2004 draft. He also has caught 407 passes for 3,324 yards and eight touchdowns.

Jackson, who has been to three Pro Bowls, was negotiating with the Green Bay Packers and the Falcons.

Jackson played on some pretty poor teams in St. Louis and wanted to play for a contender. The Falcons reached the NFC Championship game last season before losing 28-24 to the San Francisco 49ers.

Jackson helped the Rams reach the playoffs in 2004. The Rams defeated Seattle 27-20 in the wild-card round before getting pummeled by the Falcons 47-17 in the divisional round at the Georgia Dome.

The addition of Jackson should help improve the offense, which rushed for 87.3 yards per game last season and ranked 29th in the league. The unit averaged 369.1 yards per game, which ranked eighth in the league.

With an improved running attack, the triumvirate of receivers Julio Jones (1,439 yards, including the postseason), Roddy White (1,527) and Tony Gonzalez (1,059) could be unstoppable. Jackson has eight consecutive 1,000-yard rushing seasons and has averaged 4.2 yards per carry over his career.

He will be expected to split time with Jacquizz Rodgers, who had a strong second season.

He was a popular player with the Rams, and owner Stan Kroenke thanked him for his service with the franchise.

“For nearly a decade, Steven Jackson served as an inspiration for his St. Louis Rams teammates and our fans as he became our franchise’s all-time leading rusher,” Kroenke said in a statement released to the team’s website. “Off the field, his generosity and unselfishness improved the lives of many families in the St. Louis community. We will always be thankful for his contributions to our team and region and wish him success moving forward.”

The Falcons were elated to get Jackson over NFC-rival Green Bay.

Falcons coach Mike Smith noted that the franchise’s status around the league as a legitimate Super Bowl contender helped lure Gonzalez to return and was a factor in attracting Jackson.

“We know that the roster changes every year, but we are a relevant football team in the National Football League,” Smith said. “What I mean by relevant is you want to be in the conversation at the end of the season and having an opportunity to play in that second season because that’s what everybody is shooting for.”

By coming to the Falcons, that’s what Jackson is shooting for.