EDMONTON (CP) - The Edmonton Oilers made a major splash on day one of the NHL's free-agent signing period - but they did it with a blockbuster trade.

The Oilers acquired defenceman Joni Pitkanen and forward Geoff Sanderson from the Philadelphia Flyers on Sunday for blue-liner Jason Smith and forward Joffrey Lupul.

Pitkanen's arrival should provide a major boost to Edmonton's anemic power play, which ranked fourth-worst in the league last season with a 14.2-per-cent success rate. The 23-year-old established career highs with 39 assists and 43 points in 77 games with the Flyers last season.

"Joni is a talented young defenceman with a proven track record," Oilers general manager Kevin Lowe said in a statement. "He possesses the offensive skills we have been seeking on the blue-line and look forward to having him in the lineup."

Sanderson, a two-time all-star, had 11 goals and 18 assists in 58 games with Philadelphia last year.

The acquisitions came at a steep price in the form of Smith, the Oilers' captain and one of Edmonton's most consistent defensive blue-liners.

"As happy as we are with the addition of Pitkanen and Sanderson, it is difficult to see Jason leave us," said Lowe. "Jason has been an exceptional leader and member of the Oilers and has served proudly as our team captain."

Lupul, acquired in the trade that sent defenceman Chris Pronger to Anaheim last off-season, leaves his hometown team after a disappointing campaign that saw him post 16 goals, 12 assists and a team-worst minus-29 rating in 81 games.

The Oilers made two other moves on Sunday, signing free-agent defencemen Dick Tarnstrom and Denis Grebeshkov to one-year contracts.

Tarnstrom returns to the Oilers following a year away in the Swiss League. He played in Edmonton in 2006 and was part of the team that lost to Carolina in the Stanley Cup final.

Grebeshkov, meanwhile, was a restricted free agent. He was acquired by Edmonton from the New York Islanders for Marc-Andre Bergeron in
February.