كتب : Hatem Maher
"I like players who are versatile, and Luis can play on the left, on the right, through the middle as a centre-forward, and even as an attacking midfielder," West Ham coach Alan Curbishley told the club's official website.
"He is also very experienced, which is something I think we need and have been endeavouring to bring in.
"We have some very exciting young players, but I just felt we needed more experience in certain areas to help them out."
Although West Ham are struggling in the Premiership as they lie third from bottom with 18 points, Boa Morte believes he has made the right decision.
"Yes, I considered the fact that West Ham United are currently in the bottom three of the Premiership but even with that, I quickly decided that the opportunity was too good to turn down."
"West Ham is a massive club and I wouldn't have signed if I didn't think we could avoid relegation. I definitely believe we can improve, and I am excited about the challenge that is ahead."
The 29-year-old midfielder joined Fulham from Southampton in 2000, he helped the club seal promotion to the Premiership in his first season at the Craven Cottage.
He played 250 games for Fulham and scored 54 goals during his five-year spell with the club.