Germany's Federal Ministry for Economic Affairs and Climate Action must approve the 4.35 billion euro ($4.97 billion) sale, agreed about a year ago, by Jan. 31. Otherwise the transaction will collapse.

Siltronic and GlobalWafers said that during recent discussions with the ministry they had "not received any information as to whether and under which conditions a clearance ... for the public takeover of Siltronic AG by GlobalWafers may be issued".

Siltronic said the Ministry had also "not communicated specific commitments or conditions, under which a clearance decision ... could be issued."

GlobalWafers secured a majority stake in Siltronic last year and initially hoped to have the transaction, which aims to create the world's second-largest maker of 300-millimetre wafers, wrapped up in late 2021.

($1 = 0.8761 euros)

(Reporting by Christoph Steitz and Alexander Huebner; Editing by Cynthia Osterman)