Shares in rare earths developer Lynas Corp fell a further 2.5 per cent per cent on Friday morning after the company capped a horror week with confirmation of a full-year loss before tax of $57.2 million.

Lynas shares have now tanked by 31 per cent this week amid a surge in negative sentiment against the rare earths sector and concerns around increased operating costs as the miner waits on a pre-operating licence from Malaysia before it can start producing rare earths.