Use the EndFixedPriceItem call to end the specified fixed-price listing before the date and time at which it would normally end (per the listing duration). For e.g. you may need to use this call to pull down listing from the site if you discover that you are out of stock on that particular listing.
Here is a C# EndFixedPriceItem sample for ending a listing. This sample has been written using the .NET SDK v817.
*Prerequisite - make sure to have added an item with the SKU below
Below is the code. Corresponding SOAP request is attached with this article.