Acquisition vehicle Vallares aims to raise around £1bn to invest in oil assets and could announce its intention to float as early as this week.
The venture is backed by the former BP boss and financier Nathaniel Rothschild. Vallares is reported to be the 'sequel' to Rothschild's Vallar, a mining investment vehicle that listed last summer and is now worth £2.5bn.
Finsbury handled PR around the launch of Vallar and has been charged with managing media relations around Vallares without a pitch.
Finsbury partner Ed Simpkins will lead the account, having worked on the Vallar float.
The venture marks a return to public life for Hayward after he stepped down from BP in October 2010, having presided over the disastrous Deep Water Horizon tragedy and its aftermath.
Earlier this year Hayward took a non-executive director role at Glencore. The commodity giant's £36.7bn float was also advised by Finsbury.
The Vallares board hopes to float the vehicle in the pre-summer IPO period, despite a number of financial PR bosses admitting that the IPO window was likely to be shut until September.
There had been high hopes that a strong pipeline of planned London listings would boost the sector, but a number of IPOs, such as Russian Helicopters and Euroset, were pulled or postponed earlier in the year because of tough market conditions.
Despite the market gloom, Russian port operator Global Ports Investments announced this week plans to raise US$750m with a London listing.
The company, which plans to sell 25 per cent of its equity to investors, has called in Holloway & Associates to handle comms around the proposed float.