The Cowley-built Mini has set another production record at the plant, official figures show.

Last year 174,366 vehicles rolled off the production line compared to 160,037 in 2002 -- a rise of nine per cent.

Bosses admit the plant's capacity is about 180,000 cars a year. This means a production rise of just 3.2 per cent would see the plant stretched to it limits.

But plant spokesman Angela Stangroom said: "We are aware of the production constraints and we are doing what we can to balance demand for the 70-odd markets the car is sold in."

BMW directors are reluctant to extend production capacity at the plant, since it would mean further major investment on top of the £230m that was ploughed in less than three years ago, when production started.

Meanwhile, sales across the world are continuing to boom. BMW management are predicting 2004 will be another record year which will be boosted by the introduction of the soft-top convertible Mini.

A company statement said the car "again surpassed expectations" with 176,465 cars sold -- up 22.4 per cent on the 2002 figure of 144,119.

Ms Stangroom added that the recent strength of the pound and the euro against the dollar, which makes British goods more expensive in the US, had not had a noticeable impact on sales.

She said: "Last year we sold 35,000 Minis in the US compared to 25,000 the year before. The underlying trend is for revenues to grow."