China Petrochemical Corp, known as Sinopec Group, said Friday that it has signed a deal with Australia Pacific LNG Pty Ltd (APLNG) to purchase 7.6 million tons of liquefied natural gas annually for 20 years from 2016 from APLNG's gas reserves in Queensland.

The purchase amount is up from the 4.3 million tons the two companies had agreed to in April, according to a statement on Sinopec Group's website.

Meanwhile, the group reached a subscription agreement with APLNG to raise its stake in APLNG to 25 percent from 15 percent, while ConocoPhillips' and Origin Energy's stakes will fall to 37.5 percent, respectively, the statement said.

The subscription agreement is subject to approvals by the Chinese government and Australia's Foreign Investment Review Board.

APLNG is a three-way joint venture and currently meets 40 percent of Queensland's natural gas demand.