The former England international spent the whole of last season on loan at the Hawthorns, and the club has now confirmed that they are trying to secure a permanent deal
Foster enjoyed a successful spell on loan at the Hawthorns last season, missing just one Premier League match as the Baggies finished a respectable 10th in the table.
Sporting and technical director Dan Ashworth confirmed that the club have now initiated negotiations with Birmingham over a permanent deal for the former Manchester United player.
"We've started discussions with Birmingham City and we hope we can find a solution that suits them and suits us," Ashworth told the Express & Star.
"If we can't, then no problem we'll have to move on, but it's down to discussions with them.
"As with every transfer, the selling club has 'X' [price] in mind and the buying club only value [the player] at 'Y' so you hope that you find a tipping point that suits both parties. If you don't then the transfer doesn't happen."
Tottenham and Queens Park Rangers are also reportedly interested in Foster, but Ashworth is not expecting any new competition for the 29-year-old’s signature.
"Ben hasn't suddenly appeared from Mars," he pointed out. "He played 37 Premier League games last year and 38 the year before so he's been on everyone's radar.
"That's not a concern, he's been there for everyone to see and everyone knows where he is."