The US government says the trade deficit surged to a larger-than-expected $40.18 billion in December, the biggest imbalance in 12 months. The wider deficit reflected a rebounding economy that is pushing up demand for imports. The Commerce Department said the December deficit was 10.4 percent higher than the November imbalance. It was much larger than the $36 billion deficit that economists had expected. For all of 2009, the deficit totaled $380.66 billion, the smallest imbalance in eight years, as a deep recession cut into imports. However, economists believe the deficit will rise in 2010 as US demand for imports outpaces US export sales.