Last week, the telecoms firm announced a financial restructuring agreement in order to stave off collapse.
Pluthero, a former Dixons director, came up the idea for Freeserve, which revolutionised the UK internet market by offering subscription-free access to the internet and charging users for telephone calls only.
Freeserve launched its service in the UK on September 22 1998 and was widely credited with kickstarting the UK internet gold-rush. The phenomenally successful free internet service from Dixons had 500,000 accounts within 11 weeks and quickly rose to sign up more than 1.5m.
Pluthero has had plenty of previous dealings with Energis -- it was Freeserve's partner when it first launched.
He joins a new management team, which includes former Asda supermarket chairman Archie Norman MP. Norman was announced last week as the firm's new chairman.
Industry commentators are suggesting that the two are being brought in to help turn the company around and prepare for it to be sold off.
The analysis is based on the track record of the two, which has seen them both involved in sell-offs in their former jobs.
Norman is seen as the man who turned round Asda and then sold it to US grocery giant Wal-Mart, while Pluthero sold Freeserve to France Telecom-owned internet service provider Wanadoo.
The two executives will try to rejuvenate Energis, which this year put itself up for sale after its debts grew too large to pay back its bondholders and 16 bank lenders.
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