Buffett's No Godfather to Bond Insurers

So far, MBIA has been the one insurer that has had some luck raising capital over the past few weeks, securing $1.5 billion from private equity firm Warburg Pincus since December. Armonk-based MBIA raised about $2 billion via a preferred share offering and a surplus notes sale.

A rescue for bond insurers also has been sought by New York Insurance Superintendent Eric Dinallo, but no concrete plan has come to fruition. CNBC said on Tuesday that Buffett's plan came about due to a conversation with Dinallo, who appeared to endorse it.

Insurers have 30 days to accept the offer or find one better than Buffett's proposal, he said on CNBC.