Investors in Genesis Energy's capital bonds have opted to sell back to the company bonds with a face value of $77.2 million rather than accept a lower interest rate.
That is nearly 28% of the $275 million in 30-year bonds the power company sold in the first half of 2011 and which paid 8.5% interest.
The new bonds Genesis has issued to replace them pay only 6.19% interest.
Genesis has sold $1.2 million of the bonds to other investors and now has $200 million of the new bonds on issue.
Genesis used a provision buried in the fine print of the 2011 prospectus allowing it to buy back the bonds early if international ratings agency Standard & Poor's changed the way it treats capital bonds, a change which happened earlier this year.