Global broker Aon has endured a difficult third quarter, earning a 3% increase in net profit of $US120 million ($135 million).

While it was an improvement on the $US117 million ($131 million) banked in the third quarter of last year, Aon reported ongoing challenges as a result of the global downturn.

That was reflected in net investment income which fell 69% during the period to $US28 million ($31 million). Total revenue fell 2% to $US1.8 billion ($2 billion).

For the first nine months, net profit fell 63% to $US549 million ($616 million), as income from investments slid 62% to $US81 million ($91 million).

Meanwhile No 4 global broker Arthur J Gallagher experienced a third-quarter profit rise of 10%, but CEO Pat Gallagher says the continuing soft market environment in the US is a challenge.

The company reported a profit of $US41.6 million ($46.6 million) on revenue of $US439.5 million ($490 million). The result compared with a $US37.8 million ($42.1 million) profit in the corresponding period last year.