PGS has clinched an agreement to delay instalments and maturity of debt totalling $1.2bn.
But legal action remains a possibility if the Norwegian seismic survey vessel owner cannot bring a minority of rebel banks on board.
PGS called the agreement in principle an "important milestone".
All lenders involved in its $300m export credit facilities have signed up, as well as 81% of banks in its $350m revolving credit facility (RCF) and 62% of those involved in its $520m term loan B facility (TLB).
