UPDATED August 2024.
Founded in 1911 and located in Grand Rapids, Michigan, Wm. B. Eerdmans Publishing Company is an independent publisher of religious books. They have a large range, including academic books and reference works in theology, biblical studies, and religious history to popular titles in spirituality, social and cultural criticism, as well as literature. They are primarily a print publisher with excellent distribution. My local independent bookstore regularly carries a number of their titles.
They are very open about their philosophy, which I have quoted in full below.
William B. Eerdmans Sr., our founder, believed that responsible viewpoints from across the religious spectrum should be given opportunity for expression and that high literary and intellectual standards were of utmost importance. His publishing company continues to operate according to these beliefs. Thus, deeply rooted in the historic Christian tradition, ecumenical in spirit, open to emerging dialogue with other faiths, Eerdmans continues to commit itself to the life of the religious academy, to the church, and to the role of religion in culture.
To read their complete submission guidelines for submissions of adult books, please go here. They try to respond to all submissions in eight weeks. They do not respond to submissions of books that they are not interested in, and only accept mailed submissions.