underwrite

verb

the London-based company which underwrote the deal has crashed:

sponsor, support, back, insure, indemnify, provide security for, take the risk for, subsidize, contribute to, pay for, provide capital for, finance, fund;

sanction, agree to, approve, confirm, ratify, validate, authenticate, certify, seal, guarantee, warrant, accredit;

informal foot the bill for, pick up the tab for;

North American, informal bankroll.

underwrite Oxford Dictionary of English