An extendible option in which the right to extend the maturity date is held and exercised by the option seller (writer) when the option is at-the-money or out-of-the-money (from the seller’s perspective) at the maturity date, without any adjustment to the initial premium of the option. That is, neither the premium is increased nor a portion of it is waived. This option may extend automatically at the original expiration date if a specific condition, such as the option being out-of-the-money, is met. No extra premium will be paid at the time of extension.

This option is also known as a seller extendible option.