Sebastien Haller has passed his West Ham medical and will sign a five-year contract in a club-record £45m signing, Sky Sports News understands.
The Frenchman had an impressive season in Germany - scoring 15 goals in the Bundesliga and five in the Europa League - as Eintracht Frankfurt made it to the semi-finals, where they lost to eventual champions Chelsea.
The Bundesliga club confirmed Haller was due for a West Ham medical on Tuesday morning.
"Eintracht and West Ham have agreed terms for the transfer of Sebastien Haller," the Bundesliga club tweeted. "Haller has now been cleared to undergo a medical in London. If all goes to plan then Haller will sign with the Hammers."
Haller originally joined the German club from Utrecht for £6m after breaking through the youth ranks at French club Auxerre.