Samaras has arrived at the Midlands club on a free-transfer after leaving Celtic in pre-season following six years with the Glasgow giants, having arrived at Parkhead from Manchester City in 2008.

However, the 29-year-old is not expected to feature in Saturday's trip to Southampton where the Baggies will be looking to bounce back from their opening day defeat by Tottenham Hotspur.

"We've signed a player with vast experience and I'm delighted to welcome Sami to the club," Baggies' coach Alan Irvine told the club's official website.

"He has played a lot of football at the highest levels - Champions League, European Championships and World Cups -- and the feedback we've got on him, from people like Neil Lennon, states he thrives on the big occasion.

"He will certainly play in plenty of those in the Barclays Premier League.

"Georgios has played in big games for a Celtic team that have often had a lot of the ball and have had to work hard to break the opposition down.

"But he has also shown another side to his game in other matches when they haven't seen as much of the ball."

Samaras's arrival follows that of �10 million ($16.58 million dollars, 12.49 million euros) club-record signing Brown Ideye.

And with Victor Anichebe and Saido Berahino also in the West Brom squad, Irvine was happy with the balance of his forward line-up.

"We have now got four strikers with different qualities who can be used in different ways," Irvine said.

"That's great for us, because we need to have flexibility, the option to approach games in different ways and cover for injuries," the Scot added. "I'm absolutely delighted with the four strikers we have."

Samaras scored 73 goals in 249 appearances for Celtic, winning four Scottish Premier League titles with the Hoops.

He helped Greece to the last 16 of the World Cup in Brazil and has scored nine goals in 78 appearances for his country.

Samaras cost City �6m in 2006 but scored just 12 goals in 65 games before moving to Scotland.