US rapper LL Cool J has been forced to withdraw from Janet Jackson's US tour because of scheduling conflicts.

The rapper had been opening for Jackson on the jaunt, which began last month.

As previously reported, a number of dates were rescheduled at the beginning of October after Jackson suffered an illness associated to vertigo.

Symptoms of Jackson's illness had been dizziness and imbalance, her manager revealed.

Jackson is expected to add extra dates to her Rock Witu tour. At present, it is not clear who will replace LL Cool J as the support act.

(by Jason Gregory)