Mark Wilson has quit as chief executive of Aviva after Britain’s biggest insurance company decided it was time for new leadership.

Aviva’s non-executive chairman, Sir Adrian Montague, will step up to an executive role and run the company until a replacement is found. The group said it hoped to recruit someone within the next four months.

Wilson, a New Zealander, took the helm in January 2013 after his predecessor Andrew Moss was ousted by shareholders frustrated with the insurer’s poor share price performance.

Wilson, who is on a pay and bonus package of up to £6.5m, has been put on immediate gardening leave for the next six months. However, he will assist with the transition until his employment ends on 9 April.

He will receive his £1m annual salary over his 12-month notice period, along with a pro-rated cash bonus for 2018 (his bonus last year was £1.9m). On top of this, Wilson will receive share bonuses worth £3.4m when they vest over the next three years, but has lost unvested awards of £8.5m under the long-term incentive plan. He will also get up to £10,000 towards legal fees relating to his departure.

Montague said Wilson “leaves the group in a far stronger state than when he joined”, but added: “There is much further to go in accelerating our strategic development and enhancing shareholder value. We have agreed with Mark this is the right time for a new leader to ensure Aviva delivers to its full potential.”

Wilson’s departure comes after anger over the company’s plan to redeem “irredeemable” preference shares earlier this year. It was forced to abandon the plan after shareholder protests and the Financial Conduct Authority is investigating whether Aviva broke market abuse rules. Wilson has also come under fire for his decision to take a board seat at rival asset manager BlackRock.

Wilson said: “When I joined Aviva, the company was in poor health. Aviva is very different today. I have achieved what I wanted to achieve and now it’s time for me to move on to new things.”

Barrie Cornes, an analyst at Panmure Gordon, said Wilson’s departure did not come as a huge surprise. “After an initial bounce in the share price shortly following his arrival the shares have flatlined for the last give years. Aviva seems to have lost its strategic direction in recent times and as such we believe the change will probably be well received.”

Ashik Musaddi, a European insurance analyst at JP Morgan Cazenove, said Wilson had delivered a good turnaround at Aviva.

“ In line with the share price performance of UK life peers, Aviva’s shares have been under pressure as well, which in our view is partly driven by Brexit-related concerns and partly related to lack of growth visibility. Aviva has market-leading positions in businesses like pensions, annuities, non-life business and we believe Aviva should be able to capture growth in near future.”