One of Italy's most popular Catholic magazines will apologize to its readers for carrying an ad that shows a woman's naked bottom, the magazine says Tuesday.

Controversy erupted when Famiglia Cristiana, whose title means "Christian Family," showed nudity for the first time in its pages.

Naked bodies are a common feature in many non-religious Italian magazines in both advertising and editorial content.

"Modesty and chastity are important values for us and we are not giving them up," editor Antonio Sciortino writes in a message.

The ad, for a maker of ventilation machines, shows a naked bottom through a misty glass shower door. "If you want to see clearly, call an electrician now," reads the text.

Sciortino initially defended the magazine's decision to run the ad but backed down after complaints from readers.