Scharner bags West Brom move
West Brom, who have won one and lost two of their opening three matches since returning to the Premier League, said on their website he had been signed to "increase competition in central midfield."
The 30-year-old, who can play in defence or midfield, has been a free agent since leaving Wigan Athletic at the end of last season.
West Brom manager Roberto di Matteo told the website: "He is exactly the type of player we've been looking to bring in because he is a proven Premier League player, having performed consistently well in the top flight for the last four and a half years."
He is West Brom's ninth permanent signing of the summer but the transfer was one of the few to be completed on a slow, penultimate day of trading in England before the transfer window closes on Tuesday.