Ryder got a two-year, $7 million deal with Dallas after posting eight goals and nine assists in the playoffs for the Stanley Cup-champion Boston Bruins. He had 18 goals with 23 assists in 79 regular-season games.
"We're very excited about the additions we made," Stars general manager Joe Nieuwendyk said. "We identified the players we wanted to acquire and were able to get them. We've added six good players to our club and we feel we have improved our overall depth. We did a lot of research, and today was an important day for us."
Dallas is expected to lose center Brad Richards, maybe the most highly coveted free agent on the market. The Stars will be unable to re-sign him while in the midst of an ownership change and bankruptcy.
Fiddler, a nine-year veteran who played in Phoenix last season, got a $5.4 million, three-year contract. Pardy gets $4 million over two years, while Souray ($1.6 million), Dvorak ($1.5 million) and Dowell ($800,000) all got one-year deals.
Ryder played four seasons in Montreal before the last three in Boston. He has 162 goals and 172 assists in 549 career games. He has never finished a season with fewer than 30 points.
"Michael Ryder is a veteran player who brings scoring punch to our offense," Nieuwendyk said. "He's a Stanley Cup champion and will be a great addition to our leadership group."
Fiddler has 59 goals and 86 assists in 452 career games, the last two seasons in Phoenix after seven in Nashville.
Pardy spent the last three seasons with Calgary, where he had four goals, 22 assists and 141 penalty minutes in 147 games. He played part of the 2005-06 season in Las Vegas under new Stars coach Glen Gulutzan.
Dvorak has played 1,118 NHL games over 15 NHL seasons. Before being dealt to Atlanta at the trade deadline, he had spent 3 1/2 seasons with Florida.
Earlier this week, Souray was placed on unconditional waivers by Edmonton, where he had one season left on a $27 million, five-year deal signed in 2007. He played 40 games last season for Hershey in the American Hockey League, but none for the Oilers.
Dowell had six goals and 15 assists in 79 games for Chicago in his first full NHL season.