Marsh & McLennan CEO Dan Glaser has warned of “bumps” ahead as JLT is integrated but says the combined group will be better positioned than either business was before the acquisition.

“To be clear, we are not promising perfection,” he said during a first-quarter results conference call.

“There will be bumps and we could see an impact on growth during the integration process. That’s fine. We will sort it out and press forward as we work to build something special.

“In addition to JLT, we will continue to execute our broader growth strategies.”

Marsh completed the deal last month, creating a group that places more than $US100 billion ($140.5 billion) of property and casualty insurance and reinsurance premium globally, and with a reach extending to more than 130 countries.

“JLT brings us an influx of talent with complementary capabilities, giving us more depth in almost every part of the organisation,” Mr Glaser said. “We are co-locating our colleagues to enhance opportunities for collaboration.”

He rejected concerns about the “dis-synergies” that often follow large acquisitions as some people leave newly combined groups.

“We’re getting more than 10,000 talented colleagues.

“And yes, sure, we’ll lose some who decide they’d rather work in a different environment, but in my view, we’re the employer of choice in our industry.

“And our leadership team, part of their principal job is to create a culture and environment that attracts and retains the top talented people in our space.”

He says the group was encouraged by strong finishes to last year for both companies, and by Marsh & McLennan’s good start to the March quarter.

Marsh & McLennan’s net profit grew to $US716 million ($1 billion) in the first quarter from $US690 million ($969 million) a year earlier.

The risk and insurance services unit, Marsh, grew revenue by 5% on an underlying basis to $US1.7 billion ($2.4 billion), including growth of 8% in the Asia-Pacific.

Marsh CEO John Doyle says pricing on average was up about 3% in the quarter, but in most regions the gain was only 1-2% and there is not a “hard market by any stretch”.

“Australia is probably the one exception, where prices are up on average in the low double-digit range across various lines of business,” he said.

Reinsurance broker Guy Carpenter’s underlying revenue grew 6% to $US663 million ($931 million) in the quarter.