The fashion chain Jaeger collapsed into administration yesterday, putting 700 high street jobs at risk. The group's directors have appointed AlixPartners to oversee the process following failed attempts by the company's private equity owner, Better Capital, to sell the struggling business.

Jaeger – which employs around 680 staff across 46 stores, 63 concessions, its London head office and a logistics centre in Kings Lynn – had been on the market for around £30m.

However, no buyer materialised and last week Better Capital sold Jaeger's debt to a company understood to be controlled by the retail billionaire Philip Day, who heads up Edinburgh Woollen Mill.

Jaeger was founded as Dr Jaeger's Woollen System Co Ltd by businessman Lewis Tomalin and says its clothes have been worn by famous figures from explorer Ernest Shackleton to Marilyn Monroe.

Insiders now expect most of Jaeger's stores to close down, although the brand is likely to survive as part of the Edinburgh Woollen Mill stable, which also includes Jane Norman, Peacocks and Austin Reed.

Joint administrator Peter Saville, of AlixPartners, said: "Regrettably despite an extensive sales process it has not been possible to identify a purchaser for the business. Our focus now is in identifying an appropriate route forward and work with all stakeholders to do this. We will ensure that we communicate further as this process unfolds."

Better Capital, which is headed up by private equity baron Jon Moulton, acquired Jaeger for £19.5m in 2012, but the firm has struggled under difficult conditions for high-street fashion retailers.

Last year the firm said that total annual sales fell from £84.2m to £78.4 m, while it booked a pre-tax loss of £5.4m, according to accounts filed at Companies House.