Beijing — China has imposed a sweeping restructuring on Jack Ma’s Ant Group, the fintech conglomerate whose record $37bn initial public offering (IPO) was derailed by regulators in November, underscoring Beijing’s determination to rein in its internet giants.

The overhaul, in the works for several months, includes Ant turning itself into a financial holding firm, a move expected to curb its profitability and valuation by curtailing some of its freewheeling businesses...