A seven-year veteran, Smith signed a five-year, $22 million dollar deal with the Patriots in March 2002 after helping the team win the Super Bowl after the 2001 season.
Smith, 31, becomes a free agent Monday after renegotiation efforts failed over the weekend. The Patriots had until 5 p.m. Saturday to pick up the $500,000 option and give Smith a $2.4 million salary.
Had the Patriots picked up Smith's option, he would also have been due a workout bonus of $105,000 and his cap charge would have reached $3.972 million. But with the Patriots already tight against the projected 2004 spending limit, that cap charge likely seemed excessive for Smith, who turns 31 next month.
As it is, Smith will still count $2.025 against the salary cap for 2004 because of signing and renegotiation bonuses prorated over the final three years of the tailback's contract. Even if the team re-signs Smith later at a lower price, the $2.025 milliion in so-called "dead money" would remain on the '04 cap.
Though Smith was willing to adjust his contract, neither side could come to a resolution over his 2004 salary.
Smith rushed for just 642 yards and three touchdowns on 182 carries, and he started only six games and was inactive for three contests. But the seven-year veteran blossomed in New England's three postseason games, rushing for 252 yards and two touchdowns.
And Smith had at least 69 rushing yards in each game and posted a 100-yard performance in the AFC championship game victory over the Indianapolis Colts.
"In his three seasons with the Patriots, Antowain played a significant role in our team's overall success," Patriots coach Bill Belichick said in a statement. "He is a true professional. On
behalf of the entire organization, we wish him continued success in the future."
Smith, 31, has been the Patriots' leading rusher for the last three seasons. He scored a key touchdown in the team's 32-29 Super Bowl win against Carolina last week.
But the 642 regular-season yards represent Smith's lowest output since joining the Patriots in 2001 as a free agent. In his first two years in New England, he totaled 2,139 yards.
Smith played four seasons for the Buffalo Bills before signing with the Patriots as a free agent in June 2001. The Alabama native was a first-round draft pick in 1997 after playing at the
University of Houston.
Smith has rushed for a career total of 5,713 yards and 47 touchdowns on 1,481 carries.
A message left for Smith's agent was not immediately returned.
ESPN.com senior NFL writers John Clayton and Len Pasquarelli contributed to this report.
Information from The Associated Press was used in this report.