The online retailer THG is to strengthen its board with the appointment of an independent chair after concerns about governance and the future of the business led to a slump in its valuation. However, more than £800m was wiped off the value of the Manchester-based company, which runs websites including Lookfantastic and Cult Beauty, on Tuesday as it flagged that profit margins would be squeezed by currency changes. Shares dived 21% to a new low of 242p as analysts also pointed to a slowdown in growth at THG’s core beauty division. Simon Bowler, an analyst at Numis, said in a note: “The strong order book is encouraging but fails to offset the worsening momentum and worsening cash profile of the core businesses.” After several weeks of high-profile criticism and share price volatility, the company formerly known as the Hut Group, which is run by its multimillionaire co-founder Matt Moulding, said it had appointed the headhunter Russell Reynolds to search for a new non-executive chair. The appointment would put the group in line with best practice as recommended by the Corporate Governance Code in an attempt to quash concerns about too cosy a culture at the group, where Moulding is currently executive chairman and chief executive. The appointment would also help THG prepare for a listing on the main London Stock Exchange. It listed on the junior market just over a year ago. The company also responded to doubts about its relationship with SoftBank, which invested $730m (£530m) in THG this year, by announcing that Andreas Hansson, an executive at the Japanese investment group, would be joining THG’s board as a non-executive director. Hansson said the capability of Ingenuity, THG’s online services division, “has proven compelling” for several companies owned by SoftBank. He added: “We continue to be confident about our investment in THG and the Ingenuity investment opportunity.” THG attempted to tackle fears about poor growth prospects with a bullish trading statement, which flagged a 38% rise in revenues in the three months to 30 September, excluding the impact of currency fluctuations. It said sales at Ingenuity were up 45.5%, including a 131% rise at Ingenuity Commerce, which handles relationships with the likes of Nestlé and has been at the centre of question marks over THG’s future. There was also more detail on how much of Ingenuity Commerce’s revenues would be regular income rather than one-off fees. Moulding said: “We have delivered a strong trading performance in the third quarter and enter our peak trading period with confidence.”