"It's unbelievable," Ryans told the Houston Chronicle, which reported the signing earlier in the day. "I'm so appreciative. I still can't believe it. It shows that hard work and patience can pay off."
"I was delighted that we were able to get him signed," Texans owner Bob McNair told the team's official Web site. "As you know, he was a restricted free agent and we didn't have to sign him; he was already under contract. But he has been a real leader on defense and I think has set a good example for his teammates and has worked extremely hard. We felt like he deserved it, and we're happy for him."
The Texans also said they have re-signed defensive end Tim Bulman, a restricted free agent. Terms of the deal weren't disclosed.
Ryans will receive $26.3 million in the first three years of the deal. He will make $14.5 million the first year -- a $7.5 million signing bonus and a $7 million base salary -- and the two-time Pro Bowl pick will receive a $200,000 bonus every time he makes another all-star game, the Chronicle reported.
Ryans was the 2006 Associated Press Defensive Rookie of the Year and is the leader of a young Texans team that went 9-7 last season for its first winning record. He was a restricted free agent and hadn't signed his tender before striking the long-term deal.
Ryans made the Pro Bowl last season, when he finished with 123 tackles and one sack. He has posted at least 112 tackles in each of his four NFL seasons, and he had a career-best 155 stops as a rookie in 2006.
"It's about keeping those core players together," McNair said Wednesday. "We've got some core players on defense and we want to keep them together, and the guys on offense, we'll work hard to keep them together."
Ryans, a second-round pick from Alabama in 2006, has started each game in his career with the Texans and has 7.5 sacks, two interceptions and five forced fumbles.
The Associated Press contributed to this report.