LONDON, March 6: Oil prices retreated on Wednesday after spiking to their highest level for five months, as the market started to question how long a global producer pact restricting supply would last.

A barrel of Brent North Sea crude for April delivery fell 15 cents to 22.64 dollars, having climbed earlier in the session to $23.00 a level not seen since early October.

In New York, light sweet crude April futures gained 72 cents on Tuesday to $23.17.

The market has risen sharply in recent sessions because the Organization of Petroleum Exporting Countries (Opec) has expressed confidence that Russia would continue to observe a key pact curbing crude output.

The agreement between Opec and independent producers such as Russia, Norway and Mexico to skim almost two million barrels from world markets from the start of the year has been crucial in rebalancing supply and demand this year.

But the market was reminded Wednesday that the deal would not last for ever, as Norway signalled that it was unlikely to stick to its cutback commitment beyond the end of June.

The output cutbacks have started to make themselves felt in US crude and product stock levels, which have fallen sharply in recent weeks.

But in the latest week, crude reserves actually increased by 1.2 million barrels, according to the American Petroleum Institute (API).—AFP