The Turkish competition watchdog said Wednesday it has ​launched an investigation into 65 ‌companies in the auditing and financial advisory sector, including major global accounting firms.

The Competition Board (RK) said the ​probe includes the Turkish units of ⁠the so-called Big Four accounting firms: KPMG, ​PwC, Deloitte and EY.

In a statement, ​the authority said the probe aims to determine whether firms and professional organizations in the ​sector coordinated on service fees ​or engaged in anti-competitive practices in the labor ‌market.

The authority said it is ​examining whether ​companies ⁠shared service prices or client portfolios in ways that ​may have violated competition, whether ​they ⁠took decisions that could block market entry or distort competition, and whether they ⁠shared ​information that negatively ​affected employee rights and wages.

"The Competition Board, at its meeting on Jan. 29, 2026, decided to determine whether Article 4 of the Law No. 4054 on the Protection of Competition was violated by making price fixing and customer sharing agreements in service (output) markets, and non-poaching and wage fixing labor agreements (input) markets; exchanging information regarding both input and output markets; and also taking decisions of undertaking associations that restrict competition," the statement shared by the authority read.

KPMG ⁠and EY declined to comment, while Deloitte and PwC were not immediately available for comment.