Myer investors have punished the department store and pushed its share price to an all-time low after analysts downgraded the stock following its weak full-year results.

The company on Thursday revealed its full-year profit slumped 80 per cent to $11.9 million in 2017, driven by a $38.8 million writedown to the value of fashion brand sass & bide and a $6.8 million loss from its investment in Topshop's local franchisee, which went into administration in May.

Myer also said its "New Myer" turnaround plan revealed two years ago was taking longer than expected, with average sales growth of 0.1 per cent falling well short of its target of 3 per cent.

Shares were largely unchanged on Thursday but fell 4.1 per cent to 70¢ on Friday - their lowest point since the company listed on the ASX with much fanfare at $4.10 a share in 2009 - as analysts picked over the numbers.