Laptop PC shipments at the two largest contract notebook computer manufacturers in the world rocketed in March, the Taiwanese companies said, highlighting the continuing user uptake of mobile PCs.Quanta Computer, the bigger of the two, said it shipped 2.4 million laptops in March, an all time high for a single month at the company. Its revenue rose 31 percent to NT$51.2 billion (US$1.55 billion).The company’s main rival, Compal Electronics, the world’s second largest contract notebook computer maker, shipped 1.78 million laptops in March, its second highest tally ever, it said. Compal’s revenue climbed to NT$35.05 billion in March, up 51 percent from NT$23.16 billion last year.Sales of mobile PCs continued their breakneck growth in the fourth quarter of last year, when 23.57 million units were sold, up 22.4 percent over the 19.26 million sold a year earlier, according to market researcher iSuppli. Technology Industry