Skadden, Arps, Slate, Meagher & Flom sat atop three separate rankings of legal advisers for M&A deals based on total transaction value in the first half of the year.

The firm took the lead in the so-called league tables released this week by Bloomberg, Thomson Reuters and Mergermarket, thanks to its work on three of the biggest announced transactions since the start of the year: Comcast’s $68 billion buy of Time Warner in February, Valeant Pharmaceuticals’ $54 billion bid for Allergan in April, and Medtronic’s $46 billion acquisition of Covidien in June.

Skadden represented Time Warner, Valeant and Covidien in those deals.

On the firm’s heels in the first-half rankings were Freshfields Bruckhaus Deringer, Sullivan & Cromwell and Simpson Thacher & Bartlett, in varying order. Not surprisingly, most of these firms were also advising on the same deals that helped launch Skadden into first place. Simpson advised Comcast’s financial adviser JP Morgan on the Time Warner deal; S&C advised Valeant alongside Skadden in the Allergan deal; and S&C advised Covidien alongside Skadden in the deal with Medtronic, which was advised by Freshfields.

AT&T’s $66 billion bid for DirecTV also influenced Simpson’s and S&C’s placement in the first-half rankings, with Simpson advising DirecTV while S&C counseled AT&T.

S&C snagged the third spot in both Mergermarket’s and Bloomberg’s reports this week but took second place in Thomson Reuters’ ranking.

Freshfields came in second in Mergermarket’s ranking and third in Thomson Reuters’ ranking, while Bloomberg put the firm in fifth place and gave second place to Simpson Thacher.

Davis Polk & Wardwell and Latham & Watkins both fell out of their top spots from last year’s first-half rankings. Davis Polk, which claimed first place in both Bloomberg and Mergermarket’s reports in 2013 based on deal value, dropped to the eighth place on Bloomberg’s ranking and ninth place on Mergermarket’s. Latham & Watkins lost its second place spot in Mergermarket’s first-half report last year, slipping to sixth place this year.

As The Am Law Daily has reported in the past, Bloomberg, Thomson Reuters and Mergermarket rely on different criteria when compiling their rankings, making the league tables primarily useful as a broad guide to which law firms are most active in the M&A market in a given period.

All three reports also examine the global M&A market as a whole, with Thomson Reuters reporting this year’s first-half as the highest valued half-year since 2007, with $1.8 trillion worth of deal work. That represents a 73 percent increase from last year in the same period and also marks the strongest first-half percentage gain since 1998.

According to Thomson Reuters, 18 percent of M&A deals in the first half of 2014 occurred in the health care sector, the largest percentage by industry. The value of the deals in this year’s first half have already exceeded the $274.8 billion full-year record that the sector set in 2007.

All three reports also ranked legal advisers by volume of transactions for the first half of this year. Bloomberg and Thomson Reuters gave the top three spots to Jones Day, Kirkland & Ellis and Latham & Watkins in descending order. Mergermarket ranked Kirkland & Ellis in first place, followed by DLA Piper and Latham & Watkins.