Avast Software has agreed to buy its anti-virus rival AVG Technologies N.V. in a $1.3 billion deal. Avast says it is ready to pay $25 per share in cash for Amsterdam-based AVG.

The deal is meant to "gain scale, technological depth and geographical breadth," according to Avast. It aims to "take advantage of emerging growth opportunities in internet security as well as organizational efficiencies" with a goal to becoming serious competition for the global leaders in the internet security business.

The companies have over 400 million users combined.

Avast says the transaction is expected to close between Sept 15 and Oct 15.