It is in the form of third-party guarantees which protect against losses up to a particular fixed level. This is available in the form of a corporate guarantee, a letter of credit from a bank or a bond insurance. Though the third-party guarantee is referred to as "first loss protection", it is generally not used as a primary protection.
For example, if in a Rs.100 crore asset-backed securities deal, 10% is guaranteed, then for any losses that are in excess of 10%, the sponsor will not be liable. Thus, we see that an asset-backed security which has an external credit support is prone to credit risk of the third-party guarantor. If the third-party guarantor undergoes a downward change in credit rating, then the rating of the issue will also be lowered even if the performance of the entire structure is intact. This is because of the general practice the rating agencies follow by which the credit quality of the issue is assessed to be only as good as the lowest link in credit enhancement.