The Sweden international had fallen down the pecking order at the Hawthorns and, after the Baggies signed Thievy Bifoum on deadline day, is allowed to seek a new club
Rosenberg moved to the Premier League in August 2012 after five years with Bundesliga club Werder Bremen but failed to make an impression and is reported to be close to a move to his first club, Malmo.
In 33 appearances for the Midlands side, the Swede failed to score once.
West Brom sold Shane Long to Hull City in January but boosted their striking ranks on deadline day with the signing of Thievy Bifoum from Espanyol and, after slipping down the pecking order at the Hawthorns, Rosenberg has moved on in search of pastures new.
A club statement read: "Markus Rosenberg has had his Albion contract cancelled by mutual consent and is now a free agent.
"The club would like to thank Markus for his efforts over the past 18 months and wishes him well in his future career."