Kirkland & Ellis advised on corporate transactions that were valued at more money than any law firm in the first quarter of 2019, according to a new report from Mergermarket. The report also showed a 15 percent decline from 2018 in the value of deals in the first three months of the year.

A booming market for public mergers and acquisitions and private equity deals has in recent years been a boon to more than a handful of Big Law firms. But there were some troubling signs in the first quarter report, including the first time since 2016 that global deal value failed to grow from the prior year.

The total number of deals in the first three months of the year was down 30 percent from the same period last year. That trend also showed up in the U.S. The world's largest market for corporate transactions recorded the fewest number of first quarter deals in the past five years, Mergermarket said, despite those deals being valued in-line with a record 2018.

Kirkland began 2019 where it left off last year: Atop the Mergermarket ranking for the number of deals it advised on. The firm handled 127 U.S.-based deals, which was more than twice the 60 deals handled by its closest competitor, Jones Day.

The Chicago-founded firm known for its large practice representing mid-market private equity firms also made a considerable jump in the value of the deals it advised. Kirkland rose from No. 17 in the first quarter of last year to No. 1 this year, as the deals it worked on were valued at nearly $190 billion—a 135 percent increase from last year's three-month period.

Trailing Kirkland in the global deal value league tables were a number of New York white shoe firms. Simpson Thacher & Bartlett; Davis Polk & Wardwell; Wachtell, Lipton, Rosen & Katz; and Fried, Frank, Harris, Shriver & Jacobson rounded out the global Top 5 ranked by deal value.

Firms ranked six through 10 were: Sullivan & Cromwell; Jones Day; Skadden, Arps, Slate, Meagher & Flom; Slaughter and May; and Cleary Gottlieb Steen & Hamilton.

Among the top 20 firms ranked by the number of U.S.-based deals, only one saw a net increase in deal count: Simpson Thacher.

In total, there were 3,558 transactions worth $801 billion in the first three months of the year, compared to 5,085 deals worth $943 billion in the same period last year.

Private equity firms also saw a marginal dip in activity, with 629 deals valued at $103 billion in the first three months of the year compared with 920 deals worth $107 billion in the same year-ago period.