There was one caveat: he was not to enter into a merger or otherwise weaken the Roche family's control of the firm.

LSE outbid Markit, a financial-information firm, to clinch the deal, making up for a failed merger with TMX, a Canadian bourse, earlier this year.

That said, the firm (formed from a merger of two rivals, Sirius and XM, last year) has proved adept at offering content that people will pay for.