Global broker Aon has recorded a 24% rise in third-quarter net income to $US275 million ($392.4 million) from $US222 million ($316.8 million) a year earlier, aided by increased revenues and a decline in expenses.

Total revenue increased $US6 million ($8.6 million) to nearly $US2.4 billion ($3.4 billion) in the three months to September while expenses fell 4% to $US1.9 billion ($2.7 billion).

The broker’s key Commercial Risk Solutions unit enjoyed organic revenue growth of 2% during the quarter, buoyed by strong retention and management of the renewal book portfolio.

“Results also reflect strong growth in core [property & casualty business] in the US, and a decline in the more discretionary portions of our book globally, including transaction liability and construction,” Aon says.

“On average globally, exposures and pricing were both modestly positive, resulting in a modestly positive market impact overall.”

A breakdown of how the various business units performed showed Commercial Risk Solutions made $US1.04 billion ($1.5 billion) in revenues, down 1% from a year earlier.

Reinsurance Solutions achieved a 10% rise in revenues to $US321 million ($458 million), Retirement Solutions suffered a 3% fall to $US468 million ($667.8 million), Health Solutions grew 1% to $US282 million ($402.4 million) and Data & Analytics Services was 3% higher at $US278 million ($396.7 million).

CEO Greg Case says the third quarter results “demonstrate the resilience” of the business model and expects the acquisition of Willis Towers Watson to support future growth.

“In an increasingly volatile world, our pending combination with Willis Towers Watson will accelerate this proven strategy and establish the combined firm as a preeminent partner to help clients navigate today's most pressing issues and the long-tail risks we will face in the future,” Mr Case said.

Aon expects to complete its purchase of Willis Towers Watson in the first half of next year, pending clearing clearance of regulatory and other conditions.

When Aon announced the all-stock acquisition in March, the deal was valued at about $US29.9 billion ($42.7 billion).