Big Four accounting firms led by PwC topped the pack this year among the best-regarded alternative legal service providers, a new survey shows.

PwC Legal, which recently announced an affiliation with immigration law firm Fragomen, was No. 1 in the Global Alternative Legal Brand Index compiled by legal research firm Acritas.

Thomson Reuters, last year’s leader, was pushed into second place. Deloitte Legal, EY (the former Ernst & Young), KPMG Legal and Axiom followed.

PwC gained notice in September 2017 when it launched a U.S. law firm called ILC Legal to provide services to American clients with international matters.

The next month, the accounting giant rolled out Flexible Legal Services for non-U.S. clients. It provides temporary lawyers to meet sudden demand.

The latest index underscores the active rivalry between the law firm sector and alternative providers, said Lisa Hart Shepherd, Acritas chief executive.

“It’s not just PwC Legal that both old law and new law need to fear,” she said. “ All of the Big Four have seen significant increases in brand strength over the last 12 months.”

Those increases come at the expense of law firms, and the report noted that “money is moving away” from them as in-house departments seek less expensive services and faster turnaround.

PwC competitor Deloitte Legal moved up the most of any of its legal service competitors, landing in third place.

Axiom slipped from sixth and was followed by Lexis Nexis. The index is rounded out by Lawyers on Demand, Wolters Kluwer and Gartner.

The rankings were based on input from more than 800 senior buyers of legal services at worldwide organizations with $1 billion or more in revenues.