Thornton receives US$20.25 million for an average of $6.75 million per season, his agent, brother John Thornton, confirmed. Marleau will get $20 million for an average of $6.66 million per season, according to ESPN.com.
The move ensures the Sharks' core remains in tact for at least the next two seasons after this one. Centres Logan Couture and Joe Pavelski, rookie Tomas Hertl, winger Brent Burns and defenceman Marc-Edouard Vlasic are all signed long-term.
Getting Thornton, San Jose's captain, and Marleau locked up was the next big job for general manager Doug Wilson, who reconstructed this team at last year's deadline.
Thornton leads the Sharks in points with 53 on six goals and 47 assists. Marleau, who will represent Canada at next month's Sochi Olympics, is third with 47 points on 21 goals and 26 assists.