Theologian Hans Kung, who was removed by the Vatican from his post on the Catholic theology faculty at the German University of Tuebingen, has begun teaching at the University of Chicago Divinity School.

The Swiss-born theologian is teaching a lecture course on ecumenical theology and an advanced seminar entitled, "Does God Exist?" The latter is the title of a major work by Kung, published two years ago.

As visiting professor of theology, he also will give a public lecture series.

Kung, whose commitment at Chicago is for the autumn quarter only, has been offered a permanent position by the University of Michigan in the university's religious studies program. David N. Freeman, director of that department, said Kung is considering the offer but is not expected to make a decision until some time next month, when he is scheduled to lecture on the Ann Arbor campus.

Kung, who is seen by Catholics and non-Catholics as the leading symbol of reform in Roman Catholicism, has challenged the church's ban on birth control, its refusal to admit women and married men to the priesthood and its exclusion of divorced and remarried Catholics from the sacraments. But it was his questioning of papal infallibility which, a decade ago, began a long-running battle with the Vatican's Sacred Congregation for the Doctrine of the Faith.

The battle came to a climax just before Christmas two years ago with the Vatican decree, signed by Pope John Paul II, revoking Kung's authority to teach as a Catholic theologian.