By Millie Turner Antivirus software giant Avast’s revenue and operating profit has sunk so far this year, as it looks set for a takeover by fellow cybersecurity heavyweight NortonLifeLock. Revenue dipped 0.2 per cent to $470.3m (£389m) in the six months to 30 June, due to the disposal of its family safety mobile business in last year. While operating profit plunged by $54.2m (£44.8m), from $226.7m (£187.6m) to $172.6m ($142.8m), which bosses said had been driven by higher exceptional and other costs. Avast’s billings rose marginally by 0.2 per cent to $483.7m (£400.2m) in the period. Shares in…