An asset swaption that gives the holder the right, without the obligation, to buy an asset swap package with a specific strike asset swap spread for par. This option is a type of credit spread option in which the spread is based on an asset swap spread. In other words, the holder has the right to exercise the option as a fixed-rate payer on the underlying asset swap. In this sense, the holder pays fixed and receives floating. Of course, only the positive asset swap spread will be passed on to the eligible party.

It is also known as a payer asset swaption or pay-fixed asset swaption.