FOR 24 hours, Caltex's 33 petrol stations were selling the cheapest petrols and diesel. But as with most good things, it came to an end abruptly on Tuesday when the oil company with the smallest refuelling network here raised its prices to match the bigger boys.

At 10am, exactly 24 hours after it raised prices by 3 cents a litre when others raised them by 5 cents, Caltex upped its pump rates by another 2 cents - as if abiding by an unspoken rule to be in line with its counterparts Shell, ExxonMobil and Singapore Petroleum Co, all of whom have more stations than it.

A Caltex spokesman said Tuesday's 2-cent increase was 'in response to competitive market conditions'.

With the increase, Caltex's 95-octane petrol is now $1.836 a litre before discount, its 98 is $1.91, and its premium 98 is $2.076. Its diesel is $1.353 a litre before discount.

By its move, Caltex has raised pump prices six times in three months.

The latest round of pump price rises has brought petrol prices up by about 12 cents since July. A motorist using 160 litres a month - the average here - would thus spend $19.20 more a month now on petrol than three months ago. Assuming there is no change for a year, the increase would amount to $230.40 over 12 months.