Which agencies topped Mergermarket M&A adviser rankings in the first half of 2025?

Article written by Siobhan Holt for PR Week

FGS Global overtook Brunswick as the agency that handled the most M&A work in the UK by deal count in the first half of 2025, and retained the top spot by deal value, new research shows.

The value of deals handled by FGS Global in H1 2025 was $38.9bn, down 52.0 per cent on the previous year, according to media analysis and data company Mergermarket.

Headland Consultancy, which was in third place last year, is now in second. The value of deals handled by Headland in the UK in H1 2025 was $29.2bn, down 24.1 per cent on the same period in 2024. 

At third-placed H/Advisors, the value fell 39.1 per cent to $16.9bn, while FTI Consulting Group took fourth place with a decrease of 24.6 per cent, to $16.9bn, and fifth-placed Edelman recorded a 602.5 per cent rise to $14.1bn.

FGS Global was ranked first by number of deals, with 44 handled in 2025, although this was down from 47 in 2024.

It was followed in the table by FTI Consulting (up 5 to 41 deals), H/Advisors (down 24 to 30), Prosek Partners (up 8 to 29) and Greenbrook Advisory (up 4 to 28).

Global rankings

FGS Global handled the most M&A deals by both value and volume globally in H1 2025, with 233 deals worth $359.1bn. 

Joele Frank took second place by value, with 113 deals with a total value of $235.2bn in H1 this year. 

Brunswick moved from second place to third in the ‘rankings by value’ table, dropping 32.6 per cent with 77 deals at $211.9bn.

Prosek Partners ranked fourth by value of deals, up by 117.6 per cent, and held onto the second spot by volume, with 181 deals worth $124.7bn.

Europe rankings

FGS Global also took the top spot in the Europe rankings, both by value ($142.3bn) and volume (107) of M&A transactions handled in H1 2025.

Brunswick retained second place with the value of deals handled by the agency at $117.4bn in H1 2025. H/Advisors once again came in third at $49bn, and Headland held onto fourth in the ranking as the value of deals handled by the agency was $44.6bn.

H/Advisors was second in the table of deals by volume (71), ahead of Prosek Partners with (64), and Brunswick, which lost its top spot as the number of deals it handled fell by 48 from 103 to 55.

US rankings

FGS Global held on to the top spot by value of deals in this region, despite the value falling 3.1 per cent to $296.6bn. There were also declines for second-placed Joele Frank (down 18.9 per cent to $232.4bn) and third-placed Brunswick (down 44.4 per cent to $116.4bn). However, fourth-placed Prosek Partners increased by 106.7 per cent to $115.0bn.

FGS led the table by transaction volume (with 169, up 6 on its number of deals in H1 2024), Prosek Partners was second (152), with Joele Frank in third place, handling 110 deals, down 14 from its count the previous year.

Ireland rankings

In Ireland, FTI Consulting Group shot up from 11th place to the top of the ranking by deal value ($4.8bn). Meanwhile, FGS Global held onto the top spot in the ‘deal count’ table, with six in H1 2025, achieving $403m.