Falls in contract prices for coal and iron ore, plus the impact of a rising Australian dollar have ended the recent run of monthly trade surpluses.

The Australian Bureau of Statistics revealed this morning that its preliminary estimate for April was a deficit of $91 million, a turnaround of $2.393 billion on the revised March surplus.

The value of exports fell 11% from March, and was only partly offset by a 2% drop in the value of imports. As well there were significant revisions downwards in the size of the trade surplus for March and February.

The result was much worse than the market had expected: many economists had been forecasting a surplus of varying size, but were apparently caught short by the size of the adjustment caused by the lower prices for coal and iron ore which started April 1.

Just as exports and imports helped push growth higher in the March quarter, aided by government spending and solid consumption, the first trade figures for the new quarter show a very sharp fall in the size of the surplus.

In fact the small deficit, might not have occurred if there hadn’t been a $195 million reduction in the originally estimate for the March surplus of $2.498 billion to the $2.302 million reported this morning.

There was also a $526 million cut to the value of the February surplus at $1.683 billion from the $2.109 billion originally reported. (That’s more than $700 million in cuts to the size of the surplus in the very buoyant March quarter).

It’s not clear if this information was known in time for the National Accounts, released yesterday, or the balance of Payments figures released on Tuesday for the March quarter.

And there’s a strong chance of further cuts, especially to April’s deficit estimate.

That would see the $2.3 billion turnaround end up being larger as the ABS adjusts its figures to take account of more accurate figures for the falls in coal and iron ore prices from the April 1 year. From the information in today’s report, there are more price reductions to factor in, especially with the Chinese steel mills still talking to BHP Billiton and Rio Tinto about pricing.

The value of coal, iron ore, transport equipment (cars), metals and other manufactured goods fell, as did the value of rural exports.

It was an export picture more in keeping with a modest global slump, rather than a growing world economy which the figures up to March seem to suggest to some people.

Not helping was a big, 37% fall (or $783 million) in the value of non monetary gold exports (which were only partly offset by a smaller, 32% (or $305 million) fall in the value of non-monetary gold imports). Gold imports and exports have become particularly volatile in recent months, no doubt linked to demand and world prices.

It is the first deficit since last July. The estimated $91 million shortfall though is still very low by recent levels.