BOSTON (AP) The Boston Bruins signed defenseman Dennis Seidenberg to a contract extension, rewarding the defensemen that twice helped them reach the Stanley Cup finals with $16 million over the next four years.

The team announced the deal Thursday between periods of its opening night game against the Tampa Bay Lightning.

``He's been one of our core guys since we got him,'' general manager Peter Chiarelli told reporters. ``'D' like Dennis are hard to find. The way that he plays, it's hard to find.''

The deal, which has an average cap value of $4 million, would keep Seidenberg in Boston through the 2017-18 season. He said it gives him a no-trade clause for the first 30 months, with a limited no-trade clause over the next 30 months.

Chiarelli said this week that signing Seidenberg, who could have become a free agent at the end of the season, was the organization's top priority.

``I wanted to be here. They wanted me here. Both sides gave a little bit,'' Seidenberg said after the Bruins opened with a 3-1 victory over the Lightning. ``I'm really happy to be here for five years.''

In 10 NHL seasons, plus one game, Seidenberg has 34 goals and 154 assists. As Zdeno Chara's partner on the Bruins' No. 1 defensive pairing, Seidenberg helped Boston win the Stanley Cup in 2011.

Seidenberg was sixth in the NHL in blocked shots and was third among defensemen with a plus-18 last season, when the Bruins returned to the finals, losing to the Chicago Blackhawks in six games.