LATEST: Talk show host Montel Williams has quit his long-running U.S. TV programme because the multiple sclerosis he suffers from is beginning to take a grip. The star was diagnosed with the debilitating disease in 1999, but admits it has only recently started to progress, prompting his decision to take early retirement at the age of 51. A source tells U.S. tabloid the National Enquirer, "Montel is quitting his show because he's starting to see signs his disease is progressing. The weakness in his arms and legs is increasing. He's worried that he'll have problems while taping a show. "Montel said he doesn't want that captured on tape, so he wants to step down while he's still relatively healthy. "He also wants to spent quality time with his wife Tara while he is healthy." Williams has hosted the Montel Williams Show since 1991.