Retirement doesn’t suit Sir Martin Sorrell, but making a point does

Sir Martin Sorrell spent more than three decades building his first empire.Within weeks of being ousted from WPP, which he built from a small Kent-based maker of wire baskets into the world’s biggest ad group, Sorrell began plotting his return.Last week, he announced the reverse takeover of another small listed vehicle – to be renamed S4 Capital in reference to four generations of the Sorrell family – fronting £40m of his own money to rebuild his empire.