LATROBE, Pa. &

Pittsburgh Steelers star safety Troy Polamalu signed a four-year contract extension on Monday that made him the team's highest-paid player and one of the NFL's top-paid defensive backs.




Terms were not immediately available, but Polamalu's agent, Marvin Demoff, was seeking a signing bonus in the $15 million to $18 million range &

far more than the Steelers have given any player.




Polamalu's signing was the second major contract deal by the Steelers in two days. They agreed to a five-year contract Sunday with outside linebacker Lawrence Timmons, their first-round draft pick, that guarantees him $12 million and could be worth as much as $15 million.




Polamalu was a first-team All-Pro player when the Steelers won the Super Bowl in 2005.




His contract was announced minutes before the Steelers officially opened their first training camp under new coach Mike Tomlin with conditioning tests, a much-dreaded drill that former coach Bill Cowher previously held until the second day of camp.




Polamalu, a former Southern California player, has 10 sacks and 10 interceptions during his four-season career.