The Turkish international star arrived in London earlier today to undergo his medical which he passed and he is now expected to sign a one-year loan deal.
Beşiktaş are set to receive a £5 million loan fee and the rest of their initial £13 million asking price at the end of the season if West Ham decide to activate his release clause.
The Black Eagles initially did not want a loan as they the club is currently under watch from FFP. Beşiktaş have been very careful with their finances and rejected previous loan efforts.
The Hammers increased the loan fee which convinced the Istanbul giants to go ahead and release Tore who was himself pushing for a return to the Premier League – and a reunion with Slaven Bilic.
The 24-year-old winger was one of Bilic’s brightest prospects at Besiktas and played under his stewardship for two seasons.