Optus has dusted off its M & A playbook for iiNet but is not expected to get involved in a takeover war that has already sent the Perth based telco's shares to fresh highs.

It's understood Optus has looked at its rival a number of times in recent years and has re-run the numbers now that iiNet is officially on the market.

However, as is often the case, it's believed Optus struggles to see value in iiNet at $1.56 billion.

Optus has looked at its rival a number of times in recent years and has re-run the numbers now that iiNet is officially on the market. Mayu Kanamori

The company's Singaporean parent has repeatedly shown itself to be a frugal buyer and previously missed out on smaller internet service provider acquisitions to iiNet.

And, at a time when Optus has flagged extensive capital commitment to Australia already, it's hard to see them getting involved in iiNet.