"The problem now is that we're moving too slowly on the conversion of engines for vehicles and public buses to use natural gas for vehicles," he said.

Aside from fears of fast depreciation of car engines, few vehicle owners have switched from oil to natural gas because of the limited number of NGV pumping stations and the high cost of installing an NGV tank, about Bt40,000.

Bringing in used engines from Japan and other countries would relieve the shortage, Thanong said, adding that his ministry would waive duties on them for only a short time.

Bus operators could buy the used engines and switch from expensive diesel to cheaper NGV, which should lead to lower fares for passengers, who have been suffering from the climb in oil prices, Thanong said.

While diesel sells for nearly Bt30, a litre of NGV costs about Bt10.

Sathit Limpongpun, director-general of the Customs Department, said the initiative would need the agreement of the Commerce Minis-try, which bans imports of used engines to protect the local industry. If the government has a new policy, the Customs Department will follow suit, he said.

Thanong and caretaker Com-merce Minister Somkid Jatusripitak are expected to meet soon to discuss the idea.

To rein in retail prices of fuel by reducing the refining margin, the Energy Ministry would have to ask for cooperation from oil refineries, as authorities cannot force them, Thanong said.

"It would be on a voluntary basis" and would depend on whether the Energy Ministry wants to seek help from private firms, he said.

Rising oil prices are a big worry, but inflation is not.

Oil price hikes this time have not severely fuelled inflation, thanks to the liberalisation of the retail market, he said.

Wichit Chaitrong

The Nation