Jan 11 (Reuters) - The average transaction price of new vehicles in the United States shot up nearly 14% in December from the previous year, driven by strong sales of luxury vehicles, auto industry consultancy Kelley Blue Book said in a report on Tuesday. The prices hit a record high of $47,077 last month as new-vehicle inventory remained tight following healthy consumer demand, the report said. Sales of luxury vehicles, which comprised 18.4% of total sales in December, normally increase during the last two months of the year, pushing the average prices higher, according to the report. The U.S. auto industry has been hit hard by the global semiconductor shortage and supply chain snarls, causing low inventory levels and skyrocketing prices amid strong consumer demand. For each of the last six months, the average price paid by consumers was above the manufacturer"s suggested retail price (MSRP) as dealers continue to hold prices at or above MSRP, according to the auto consultant. Meanwhile, the average price for a new non-luxury vehicle was $43,072, slightly lower than the record high set in November.