A little more than a week after reaching a tentative agreement, Manning signed the six-year extension that will keep him with the team through 2015 and pay him an average salary of $15.3 million starting next season.
Manning is guaranteed $35 million under terms of the $97.5 million extension. News of the deal first broke on Aug. 5.
"It's good to get it out of the way and not have to worry about anything else," Manning said after the Giants held their morning practice at the University at Albany. "Now it's time to get ready for the season."
The low-key Manning insisted that being one of the league's highest-paid players would not put any added pressure on him.
"My job is to play quarterback for the New York Giants and try to win games," he said. "Nothing has changed. My responsibilities have not changed. I am trying to go out there, do my part, play well and lead this team."
Giants general manager Jerry Reese said that the nine-day gap between when the agreement was announced and when it was signed was never an issue.
"It was just some small details that we had to iron out in the contract, so it has pretty much been done since it first started to be reported," Reese said.
Manning will make $9.4 million this season under the final year of the contract he signed as a rookie in 2004 as the No. 1 overall pick in the draft.
Before Manning's extension, All-Pro cornerback Nnamdi Asomugha of the Oakland Raiders was the NFL's highest-paid player on average. He agreed to a three-year, $45.3 million contract earlier this year.
Carolina defensive end Julius Peppers will be the league's highest-paid player this season with a one-year $16.7 million contract.
Manning has started the past 71 games for New York, the third-longest streak among active quarterbacks at the end of last season. During that span he also has become the first Giants quarterback to throw for 3,000 yards and at least 20 touchdowns in four consecutive seasons.
"I am happy to be here, this is where I want to be," said Manning, who was the MVP in New York's upset Super Bowl win over New England in February 2008. "I feel the Giants are one of the greatest organizations, if not the best organization in the NFL and it's an honor to be part of the Giants and play quarterback in New York. I have worked hard to try to become a better player and I feel I've done everything to help the Giants and I'm excited to know I'll be here six or seven more years."
Manning has led the Giants to the playoffs in each of his four full seasons as a starter. Last season, he led New York to the NFC East title and earned his first Pro Bowl berth, passing for 3,238 yards and 21 touchdowns.
"He's our franchise quarterback, and we've been in the playoffs for the last four years, and he's done everything we ask him to do," Reese said.
Information from The Associated Press was used in this report.