Operating income from the company's HR solutions segment rose 55 percent to $133 million as revenue increased 3 percent to $3 billion.
In 2010, Aon bought human resources specialist Hewitt Associates Inc for $4.9 billion in a bid to leapfrog rivals Marsh & McLennan
While macro economic conditions remain challenging globally, we are firmly on track to deliver improved growth in 2012, Aon Chief Executive Greg Case said in a statement.
October-December net income attributable to shareholders from continuing operations rose to $277 million, or 82 cents a share, from $232 million, or 67 cents a share, a year ago.
The company, which sponsors English Premier League football club Manchester United, earned 97 cents a share from continuing operations, before items.
Analysts expected a profit of 96 cents a share on revenue of $3 billion, according to Thomson Reuters I/B/E/S.
Earlier this month, Chicago-based Aon said it would move its headquarters to London to improve its access to fast-growing emerging markets and boost its presence in the British Capital's global insurance centre.
Shares of the company, which hit a life-high of $54.58 on April 7, 2011 lost more than a quarter of their value by last September, but have since then jumped more than 20 percent. They closed at $49.37 on Thursday on the New York Stock Exchange.
(Reporting by Aman Shah in Bangalore; Editing by Sriraj Kalluvila)