Credit Suisse First Boston (CSFB), which is leading Swiss Life's Sfr856m (e583m) rights issue launched last week, has the option to pull the deal if the troubled insurer loses its single-A credit rating.

The clause is part of the terms of the underwriting agreement in Swiss Life's rights issue prospectus. Although clauses referring to credit downgrades are standard provisions for underwriters of rights issues, CSFB's stance allows Swiss Life no room to slide.