Marsh & McLennan Cos. Inc. remained atop the Business Insurance 2015 ranking of the world's largest insurance brokers, growing its brokerage revenue 5.7% in 2014 to nearly $13 billion.

Despite competition and softer prices in the reinsurance sector and property/casualty in general, as well as foreign exchange rates that limited gains, Marsh & McLennan posted strong results through the first quarter of 2015 with net income of $482 million, an 8.8% rise over the same period last year.

“Marsh has performed well. They've had solid performance, solid margins, solid organic growth,” said Julie Herman, associate director of insurance rating at Standard & Poor's Corp. in New York. “They certainly have had their share of headwinds, but overall they have performed well.”

Despite a reinsurance market buffeted by an ongoing influx of third-party capital and new players, reinsurance brokerage unit Guy Carpenter & Co. L.L.C. “withstood the pressure in the reinsurance division fairly well,” Ms. Herman said.

“Guy Carpenter was positive organic in the first quarter of 2015, even though there are a lot of headwinds in the reinsurance market. That's because of successful new business captured to offset the declines in pricing, and also offsetting revenues they're getting from consultative services and transactional services related to the alternative capital deals,” Ms. Herman said.

A strengthening U.S. dollar has been another obstacle for international brokers with overseas businesses. The company will have to contend with foreign exchange and pension liabilities in 2015.

“While we continue to think Marsh & McLennan is the best operator in the space, we believe foreign exchange and pension liabilities will continue to present headwinds in 2015,” said Sean Dargan, vice president with Macquarie Securities Group, part of Macquarie Capital (USA) Inc. in New York, in a research note.

The company is facing increased pension costs for retirees and estimated the impact to be some $0.15/share on a fourth quarter earnings call, according to Mr. Dargan.

At the core of the firm's success is its ability to grow, said Marsh & McLennan President and CEO Daniel Glaser.

“We're a global growth company,” Mr. Glaser said. “We've been at it for 140 years, but we are absolutely a global growth company.”

Despite 2014 being a “pretty tough market,” the broker reported 5% organic growth. “That was our strongest growth in the last three years,” Mr. Glaser said.

“2014 was also a record year for new business,” he said. “That kind of business proves you can be competitive in the marketplace.”

New revenue on existing accounts together with new accounts, which Mr. Glaser described as “new new” business, topped $1 billion in 2014.

Further, Marsh & McLennan has made a series of moves during the past year to try to ensure continued growth and continuity for the firm moving forward.

In the first week of May, Peter Zaffino, president and CEO of Marsh L.L.C., was named chairman of its risk and insurance services segment, which includes brokers Marsh and Guy Carpenter.

“It's a big, fundamental change because it's essentially saying we have skills at both Marsh and Guy Carpenter that meet the needs of clients, and sometimes those skills would be better operating in a consolidated way,” Mr. Glaser said of the appointment, referring to structural changes in leadership and reporting, and skills consolidation through closer cooperation between units and improved access to resources.

Attracting and retaining high-caliber employees also is a priority.

“We think in the consultancy and insurance space that talent management becomes more and more important,” Mr. Glaser said. “I would say that the quality and number of candidates for open positions we have has never been higher.”

Another key asset for the company is its own data, Mr. Zaffino said.

“Marsh has a vast data library with more than 70 million claim records, representing losses in dozens of countries across more than 20 industries,” he said. “Our investments in capturing that data are really beginning to help our clients make strategic decisions with greater confidence.”

The firm is also investing in its private health care exchange, Mercer L.L.C.'s Mercer Marketplace.

“We view it as a tremendous opportunity for the company,” said Mr. Glaser, adding that Marsh & McLennan itself provides insurance to its employees and retirees through the private exchange.

In February, Mercer, Marsh & McLennan's benefits consulting unit, invested $75 million in a 9.9% stake in Benefitfocus Inc., a Charleston, South Carolina-based benefits technology provider.

Broker division Marsh also continues to build out its Marsh & McLennan Agency L.L.C. unit to serve the middle market.

“We feel we now have a blueprint and foundation for a high-quality national middle-market agency,” Mr. Zaffino said.

Mr. Glaser sees Marsh & McLennan as a rare species.

“There are not many companies in the world with $13 billion in revenue that don't manufacture anything,” Mr. Glaser said.