PetroChina's proposed $1 billion purchase of a 45.5 stake in Singapore Petroleum Co will give the Chinese company more leverage and flexibility in oil trading, analysts said yesterday.

As a move to gain a foothold in Asia's largest oil trading center, the deal may enhance domestic companies' influence on global oil pricing, they said.

The Beijing-based PetroChina said late on Sunday that it would buy 45.5 percent of Singapore Petroleum Co (SPC) for S$6.25 ($4.25) a share, from Keppel Corp.