Vietnam's rice exports in the first 11 months of this year rose an estimated 10.5 percent from the same period last year to a record 6.21 million tonnes, the government estimated on Thursday. The General Statistics Office said rice export revenues between January and November rose 15.8 percent from a year ago to an estimated $2.9 billion, also a record. Vietnam, the world's second-largest rice exporter after Thailand, has signed export contracts for a record 7 million tonnes of the grain this year. Some 6.66 million tonnes should be loaded by the end of the year, the Vietnam Food Association said. The record shipment so far this year, compared with around 6 million tonnes exported in 2009, left a thin stock in the Southeast Asian country, the world's second-largest rice exporter after Thailand. Asian rice prices were relatively firm this week, supported by thin Vietnamese stocks and fresh demand over recent weeks, exporters said on Wednesday. While the stock is thinning, Vietnam still has to meet loading demand for major contracts its government signed with the Philippines, Indonesia and Cuba. The loading demand has pushed domestic prices in the southern Mekong Delta food basket up even though exporters have built some stocks in advance. Prices of unmilled summer-autumn rice have been stable at between 5,500-6,800 dong (28.2-34.9 US cents) per kg in the past two weeks in the Delta, up from 4,900-6,200 dong in late October. Farmers in the delta have started planting the winter-spring crop, the highest yielding among their three rice crops a year. The winter-spring rice, most of which is for export, will be harvested from late February 2011.