Zimbell House publishing offers anthologies leaning more to the novella and novellette categories. Entry is free and selected submissions receive payment. They welcome international authors, but require submissions to be in English.
These guys are perfect to try out if you are itching to write a longer story (but don't feel like a full-blown novel).
Click HERE to view their current anthologies open for submission. The link is as always on the right hand pane as well.