FTSE 250-listed Premier Oil yesterday announced that it has disposed of its wholly-owned subsidiary in Vietnam for up to $100m (£66m). Premier will make an immediate cash payment of $45m and further payments depending on operational results. The buyer of the asset was not disclosed. “We are pleased to be delivering against our commitment given earlier in the year to rationalise our investment portfolio,” said chief executive Simon Lockett. Premier shares closed one per cent lower at 357.8p.