West Ham United are delighted to announce the signing of striker Robbie Keane from Tottenham Hotspur.
The Republic of Ireland captain has joined on an initial six-month basis, which will continue for a further two years provided the club are in the Premier League next season. He described the Hammers as a "fantastic club with a great tradition".
Keane, who watched the second half of Sunday's 3-2 FA Cup fourth-round victory over Nottingham Forest from a Boleyn Ground Executive Box, spoke of his excitement at joining the Hammers.
"I am really pleased to have signed and now I just can't wait to start training and playing football," he said. "I am ready to help West Ham United to stay in the Premier League, which is the most important thing for this club.
"I feel as fit as I ever have done in my life and I feel I have plenty left to offer at the highest level for at least the next four or five years.
"I want to help anywhere I can help the football club, whether that is in training, in the dressing room or on the pitch on a matchday. We have some good players here and I am sure we can stay up.
"When I went on loan to Celtic I scored 17 goals in 19 games and if I can do even half as well as I did there, then I'll be happy."
The 30-year-old is the fourth recruit this transfer window joining Wayne Bridge, Gary O'Neil and fellow forward Demba Ba.
He passed a medical on Saturday night before putting pen to paper after the FA Cup match on Sunday evening.
Keane, who has scored 45 goals in 104 internationals, could make his debut in Wednesday night's trip to Blackpool with a possible home bow coming next Sunday against Birmingham City. Keane brings plenty of top-level experience to the Boleyn having previously played for Inter Milan, Liverpool and Celtic.