Marian--Mah-ree-ahn, or Merien if you want to stay as close to the English pronunciation as possible. We call my friend Mary-Anne in Spanish Mariana, Mah-ree-ah-nah
Here you go >> http://soundcloud.com/yeikel/marianne
Mariana, Mary Ana, Mari Ana... there are no rules for proper names in Spanish. The Marianne is the symbol of Liberty in France. I love this name by the way.