It bought the cargoes for delivery over Oct. 8-9 at $19.8477 per million British thermal units (mmBtu) and for Oct. 23-24 at $20.2877 per mmBtu from commodity trader Trafigura, one of them said.
Three other cargoes for delivery in October and November were not awarded.
Trafigura had placed the lowest offers for a cargo to be delivered over Oct. 28-29 and another for Nov. 12-13 while PetroChina placed the lowest offer for a cargo to be delivered over Nov. 6-7.
Prices for those ranged from $20.3888 to $20.9677 per mmBtu.
Asian spot LNG prices are trading at their highest for this time of year since at least 2010 as a hot summer has cut gas inventory levels around the world.
It was not immediately clear if Pakistan LNG would issue another tender for the cargoes it did not purchase. It also has a separate tender seeking seven cargoes for delivery in October and November which is valid until Sept. 8.
Other companies that took part in the tender are Gunvor Singapore, Vitol Bahrain and Total Gas & Power.
A separate tender by Pakistan State Oil for October delivery did not receive any offers, a second source said.
(Reporting by Jessica JaganathanEditing by Uttaresh.V and Mark Potter)