Aon PLC on Friday reported higher revenue and a sharp increase in profit for the fourth quarter as several sectors of the economy grew — ratcheting up demand for insurance despite the pandemic — insurers bought more reinsurance amid a hardening market and the brokerage saw a drop in operating expenses.

The brokerage reported $2.97 billion in fourth-quarter revenue, a 2.8% increase over the year-earlier period, and a 2% increase in organic revenue, which excludes the effect of foreign exchange fluctuations and the effect of acquisitions and divestitures.

Aon’s commercial risk solutions unit, which houses its core brokerage operations, reported $1.38 billion in revenue, a 3.4% increase over the 2019 quarter and up 4% on an organic basis.

Its reinsurance brokerage division reported $197 million in revenue, up 5.3% over the year-earlier period and up 12% on an organic basis.

In other areas, the brokerage reported flat revenue in retirement solutions, a 5% increase in health solutions and a 1% decrease in data and analytics services.

Net income for the quarter jumped 39.8% to $534 million. The brokerage reported a 5% fall in operating expenses in part due to a reduction in restructuring costs following the completion of its multiyear restructuring program last year and lower travel expenses during the COVID-19 pandemic.

For the full year, revenue edged up less than 1% to $11.07 billion, and net income rose 28.3% to $2.02 billion.

The improved results stem largely from improvements in the overall economy and sentiments around the pandemic and the rollout of vaccines, Greg Case, CEO of Aon, said on a conference call Friday with analysts.

“We saw positive impacts to our revenue from construction starts and M&A activity in the U.S., as well as from employment levels,” he said.

More “discretionary” business sectors, such as travel, entertainment, and data and analytics, continued to be hit by the pandemic, Mr. Case said.

The strong growth in reinsurance was in part driven by account wins and by increased demand for reinsurance from new and existing insurers, said Eric Andersen, president of Aon.

Insurers “are looking to get support where they need it as they look to grow their own portfolio,” he said.

Aon still expects to close its pending acquisition of rival Willis Towers Watson PLC on time, said Christa Davies, chief financial officer of Aon.

Late last year,  European Union competition regulators announced an investigation into the proposed deal, saying they were concerned the acquisition could reduce competition in several different areas in which the two brokerages operate.

“We continue to work collaboratively to gain approval and are focused on achieving a result that optimizes shareholder value. We remain committed to our projected close in the first half of 2021,” she said.

The EU regulators expect to complete their investigation in May.