US cyber security firm NortonLifeLock has delayed the anticipated completion day for its buyout of London-outlined rival Avast to April 4, expressing it was awaiting regulatory nods in the United Kingdom and Spain.

The dollars-and-stock offer, valued at up to US$8.6 billion (A$12 billion) when it was initially announced in August final yr, was previously predicted to close on February 24.

NortonLifeLock’s shares have been down 2.1 % in prolonged buying and selling.

The takeover has captivated the scrutiny of Britain’s competitiveness regulator, and the agency in January introduced an investigation into no matter if the offer will reduce option for clients in the nation.

The regulator has set a deadline of March 16 for a preliminary decision.