More than a month after France's Casino Group completed the US$1-billion sale of its Big C Vietnam chain to Thailand's Central Group, officials in Hanoi have reportedly grown impatient over the late tax payment on the record deal. In a recent letter to the companies, the General Department of Taxation calculated the capital transfer tax for the deal at 3.6 trillion dong ($159 million) and threatened to block the transfer if the companies refuse to pay up, Tuoi Tre newspaper reported.