Sacha Romanovitch, the first UK female chief executive of a major City accountancy firm, will step down from Grant Thornton by the end of this year.

The company said Romanovitch would leave her job once a successor was identified.

“Following discussions with Sacha, the board has agreed that a new CEO is the logical next step to create long-term sustainable profits for the firm,” said Ed Warner, independent chair of Grant Thornton UK’s partnership oversight board.

Romanovitch said: “As we enter the next phase of our plans, following discussions with Grant Thornton’s board, we have agreed that the time is right for a new chief executive to take the firm forward. I will be working to support a smooth transition to our next chief executive, focusing on continuing to deliver sustainable value for our clients through our diverse and talented team.”

Romanovitch has worked at Grant Thornton for 28 years, becoming a partner in 2001 and becoming chief executive of the global accountancy firm’s UK business in 2015.

She introduced changes including capping her own salary at 20 times the firm’s average pay. The firm’s partnership structure was overhauled with a John Lewis-style profit-sharing scheme for all staff, rather than just partners.

Last month, an unnamed Grant Thornton insider claiming to speak for 15 partners or directors [£] leaked to several news organisations the contents of Romanovitch’s annual performance review and an unsigned complaint saying she had “misdirected” the firm.

The anonymous writer accused Romanovitch of pursuing a “socialist agenda” and that the firm had no focus on profitability under her leadership and was “out of control”.

Romanovitch responded: “A small cadre of partners will find it hard we are making decisions that will depress profits in the short-term but will help profits in the long-term … If profits get unhinged from purpose it might not hurt you now, but it will come back and bite you on the bum.”

The accountancy industry is under intense scrutiny after a series of high-profile company collapses in recent years including Carillion, which was audited by KPMG.

The UK’s audit watchdog, the Financial Reporting Council (FRC), laid out a series of changes earlier this month to tackle what it admitted was the “underlying falling trust in business and the effectiveness of audit”.

The FRC proposed that big accountancy firms could be banned from earning lucrative consultancy fees at businesses they audited and severely rebuked KPMG, finding “a deterioration in the quality of the audits that we inspected to an unacceptable level”.

The FRC is itself under intense pressure to improve its performance. It has been widely criticised as being too timid and too close to the firms it is supervising and is the subject of a government review, led by Sir John Kingman, to determine if it is fit for the future.

Grant Thornton handles the accounts of Patisserie Holdings, owner of Patisserie Valerie, which has been rocked by an accounting scandal and came close to collapse before getting a £20m lifeline from its chairman Luke Johnson.

The FRC said on Friday it was looking into the Patisserie Holdings case. The Serious Fraud Office has said separately it has opened an investigation into an unidentified individual in connection with the scandal.

In August, Grant Thornton was fined £4m by the FRC after four of its senior staffers admitted misconduct in handling the financial audits of Nichols Plc and the University of Salford.

In 2016, Grant Thornton was criticised by MPs investigating the collapse of retailer BHS for its role advising Dominic Chappell, the three-time bankrupt who bought the business a year before its demise.

Grant Thornton said that it was only doing “financial due diligence” for Chappell’s consortium in the pre-acquisition period. Its post-deal consultancy work was undertaken because it believed it had “experience of real value to share with BHS and its management”.