Grifols' American depositary receipts slumped following a report that Brookfield Asset Management plans to abandon its acquisition of the Spanish pharmaceuticals company. The stock was down 18% at $7.14 in premarket trading. Shares had already fallen nearly 25% year-to-date when the market closed Tuesday.

Brookfield Asset Management Ltd. is preparing to walk away from a plan to acquire Grifols SA over disagreements on valuation for the Spanish drug maker, according to people familiar with the matter.