The 27-year-old Wales midfielder has joined from Championship side West Brom, beaten in last season's play-off final by Derby County.

Koumas has moved for a reported fee of 5.3 million pounds (10.7 million dollars) which would represent a profit of 3 million pounds (6 million dollar) for Midlands club West Brom, who brought the player to the Hawthorns in a 2.5 million pounds transfer from Tranmere in 2002.

Koumas scored 23 goals in 141 appearances for the Baggies and also hit the back of the net 13 times during a season-long loan with Cardiff City in 2005-06.

He has now become new Wigan manager Chris Hutchings's fifth pre-season signing since he replaced Paul Jewell at the end of last term.

Hutchings has also signed Antoine Sibierski, Carlo Nash, Titus Bramble and Mario Melchiot.