WeWork, the SoftBank Group-backed startup whose meteoric rise and fall reshaped the office sector globally, sought U.S. bankruptcy protection Monday after its bets on companies using more of its office-sharing space soured.

The move represents an admission by SoftBank, the Japanese technology group that owns about 60% of WeWork and has invested billions of dollars in its turnaround, that the company cannot survive unless it renegotiates its pricey leases in bankruptcy.

A WeWork spokesperson said about 92% of the company's lenders had agreed to convert their secured debt into equity under a restructuring support agreement, wiping out about $3 billion of debt.