Sir Martin Sorrell has revealed he is in takeover talks with a number of companies as he looks to rebuild an international marketing business, weeks after he was forced out of WPP following allegations of personal misconduct.

Almost immediately after Sorrell was forced to stand down in April, having run the world’s biggest ad group for more than three decades, he began talks to stage his comeback.

On Wednesday, he delivered on his promise that it would be a case of “back to the future” – as he had hinted in a resignation letter to WPP staff last month – detailing a reverse takeover of another small listed company to use as a vehicle to rebuild his empire.

Sorrell is to take 75% control of Derriston Capital, taking the post of executive chairman, with the aim of building a next-generation WPP for the digital age.

“S4 Capital is a company that aims to build a multi-national communication services business focused on growth,” said Sorrell. “There are significant opportunities for development in technology, data and content. I look forward to making this happen.”

Derriston, which began talks with Sorrell in May, will change its name to S4 Capital. Sorrell incorporated S4 Capital, a reference to four generations of his family, in Jersey on 22 May, with £40m of his money and £11m from other investors.

A number of those investors have also signed “non-binding letters of support” to provide in principle more than £150m of further funding to fuel Sorrell’s acquisition plans.

Derriston disclosed in a financial filing that Sorrell is closing in on a number of potential acquisition targets.

“The directors of the company understand that S4 Capital is at present in preliminary discussions regarding a select number of potential acquisitions that would fit with the strategy of building a multinational communication services business,” the company said. “S4 Capital intends to target businesses focused on technology, data and content.”

Sorrell has also gone back to the future for his non-executive directors, calling in Rupert Faure Walker, who advised on the takeovers of J Walter Thompson and Ogilvy & Mather in the late 1980s, which transformed WPP, a small maker of wire baskets, into a major global force in advertising.

He has also appointed Paul Roy, the former British Horseracing Authority chairman, and the founder of the investment management company NewSmith Capital Partners.

Alex DeGroote, a stockbroker at Cenkos, believes that Sorrell will not be able to resist targeting a major WPP asset.

“It wouldn’t surprise me if he was discreetly sounding out JWT or Ogilvy, they were the anchor assets that built WPP,” he said. “Institutional investors would feel more comfortable backing the acquisition of assets known to them, like Ogilvy which has moved from the Mad Men era to digitally fit for purpose. I think Sorrell will make a headline grabbing, transformational deal within nine months.”

Sorrell has structured the deal to give himself a five-year window to grow S4 Capital and make his exit, by which point he is likely to be close to his 79th birthday.

If he can engineer a sale, takeover or merger of S4 Capital in that time frame - and the company has produced returns to shareholders at a rate of 6% - Sorrell is eligible to pocket 15% of the increase in value of the company.

Sorrell was able to bounce back so quickly because of the unusual nature of the contract he had at WPP. Instead of the standard notice period of 12 months, he or the company was able to terminate the contract “at will” with no non-compete clause.

WPP classified Sorrell as having “retired”, after deciding not to make the outcome of its investigation into misconduct allegations public, meaning he will make almost £20m in payouts from his former employer over the next five years.

The WPP chairman, Roberto Quarta, is facing an investor backlash at the company’s annual meeting next month over the Sorrell affair, with the influential advisory company Glass Lewis recommending shareholders vote against his reappointment.