Marsh & McLennan Cos. Inc. on Thursday said 2018 fourth-quarter revenue rose 1% to $3.71 billion, while full-year revenue rose 7% to $14.95 billion.

Excluding the impact of the ASC 606 revenue standard adopted Jan. 1, 2018, revenue grew 4% for the quarter, Marsh said in its earnings statement.

Organic growth was 4% for the fourth quarter, according to President and CEO Dan Glaser, speaking on the broker’s earnings call Thursday morning, adding the company’s Risk & Insurance Services business unit — which encompasses Marsh LLC and Guy Carpenter & Co. LLC — produced organic revenue growth of 6%.

He called the quarter an “outstanding finish to the year” with “all of our business units contributing” to the company’s underlying growth.

Marsh’s underlying growth rose 6% in the quarter, “the strongest quarter of underlying growth since second quarter 2012,” Mr. Glaser said.

Fourth quarter revenue at Marsh rose 6% to $1.8 billion, the statement said. Combined, the U.S. and Canada saw 7% growth, while international operations saw revenue growth of 5%, with 8% growth in Asia Pacific, 8% in Latin America and 3% in EMEA, the statement said.

Marsh saw revenue growth of 4% for full year 2018 to $6.87 billion, the statement said.

Fourth-quarter revenue at reinsurance broker Guy Carpenter rose 5% to $102 million as yearly revenue rose 7% to $1.3 billion, the statement said.

The reinsurance intermediary’s quarterly growth was its “eighth consecutive quarter of 4% or better underlying growth,” Mr. Glaser said, adding the yearly rise was “the strongest result since 2009.”

Revenue in the risk and insurance services unit totaled $1.9 billion in the fourth quarter of 2018, off 2% compared with the fourth quarter of 2017, and up 5% excluding the impact of ASC 606. For the full year 2018, revenue rose 8% to $8.2 billion, the statement said.

The unit results “combined to lift underlying growth in RIS to 6% for the quarter, the third consecutive quarter of underlying growth of 5% or more in RIS,” Mr. Glaser said.

Underlying growth of 5% for the year at RIS was “the best full-year growth we have seen since 2012,” Mr. Glaser said.

Marsh & McLennan’s net income for the quarter jumped to $153 million from $29 million in the year-ago period, the statement said.

Investment income was flat for the quarter at $12 million and moved to a loss of $12 million for the year from a gain of $15 million in 2017, the statement said. The company expects “only modest investment income “ in 2019, according to Chief Financial Officer Mark McGivney, speaking on the call.

In addition to its purchase of Jardine Lloyd Thompson Group PLC, Marsh & McLennan made 23 acquisitions worth $1.1 billion in 2018, Mr. Glaser said.

The JLT transaction is still set to close in the spring as it clears regulatory hurdles, Mr. Glaser said, adding that Marsh leadership team recently visited JLT major locations around the world representing 80% of JLT’s global revenue base.

Mr. Glaser forecast that without impact from JLT, Marsh expects underlying revenue growth between 3% and 5% for 2019.