Engine consultant Ricardo said trading conditions in its core markets have not markedly improved since the year end and it still expects first-half trading to be "substantially" lower than the same period last year.The group said in the US, a very depleted opening order book has resulted in a poor start to the financial year. In Germany, there has been an increase in discussions with clients since the summer shutdown, which the group expects should lead to increased orders in the new calendar year.China and Russia continue to be active with recent order wins and medium to large size programmes under discussion, the group said.The total order book at the end of October closed at just over £100m compared to £97m at the end of June 2009."Due to the size and profile of our orderbook and signs of an anticipated market recovery we continue to gather momentum and expect that second half trading will return to more normal levels," the group said in a company statement.