West Ham have confirmed experienced keeper Jussi Jaaskelainen has agreed personal terms with the club.
As revealed by skysports.com earlier on Wednesday, the 37-year-old has returned to the Premier League after turning down the chance to remain at Bolton following the Trotters' relegation last season.
He will move to the Hammers when his Bolton deal expires on 30 June on a one-year contract, with an option for a second year.
The experienced keeper told the club's official website: "I'm delighted to be joining West Ham United.
"After spending 15 years in Bolton it's a great new challenge and I'm really looking forward to it.
"Everything has happened really quickly. When the opportunity was offered to come to West Ham I didn't think twice and I just told my agent to sort it out as quickly as possible.
"I appreciate Bolton giving me permission to speak to West Ham before my contract was up and for the efforts the chairman made in trying to get me to stay.
"I would like to thank the fans for all their support over the years and I wish the players and, in particular, Owen Coyle all the best in gaining promotion at the first attempt."