(ShareCast News) - Shares in 21st Century dumped more than a third of their value as the company warned full-year revenue would be lower on the year, resulting in a significant loss for the 12-month period."It was anticipated that the slow start to the year would be followed by a pick-up in trading in H2 although this is proving slower to materialise," the company said.In order to mitigate losses, a programme to remove costs and accelerate the consolidation of operations commenced in H1 and is continuing.This was particularly so in areas where there was duplication or overlap resulting from the acquisition of RSL Group in May last year.Directors were considering all possible options with respect to the RSL business, 21s Century said in a statement.Separately, 21st Century confirmed an important contract renewal with First Bus, in the form of a five-yar framework agreement.At 11:49 BST, shares in 21st Century were down 36.84% to 1.5p.