PRAGUE -- A Vatican delegation arrived this week for talks with communist authorities that Roman Catholic sources said may lead to the appointment of new bishops for 10 vacant sees in Czechoslovakia.

According to the government news agency CTK, the Vatican delegation was led by Archbishop Francesco Colasuonno. It did not say who met the visitors.

At a meeting at the Vatican in December, the two sides discussed the church's situation in Czechoslovakia, where an estimated 50 to 60 percent of the 15.5 million people are believed to be Catholics despite the official policy of atheism.

In the last two months, activists among Catholics and those of other religions have reported a slight easing of the rigid control over religious activities in the country.

One source, speaking on the condition that he not be identified, said talks this week could lead to the naming of new bishops and even archbishops.

Two bishops died last fall and 10 of the country's 13 Catholic sees are vacant. The three incumbents are over 75 years old, the Vatican retirement age for bishops.

Cardinal Frantisek Tomasek, archbishop of Prague and leader of the Czechoslovak church, is 88.

Earlier this month, Tomasek gave unprecedented support to a petition circulating throughout the country that demands more religious freedom.

Thousands of people are said to have signed the 31-point petition, but no specific figures have been made available.

Colasuonno is the special envoy of Pope John Paul II for Vatican relations with East European countries.

He was in Slovakia two months ago for the funeral of Bishop Julius Gabris.

The Vatican has been unable to get government approval for any new bishops since 1973. Last October, Pope John Paul deplored the "sad state" of the church in Czechoslovakia.

The government controls religion through a federal office that licenses clerics, sets conditions for their work and regulates their salaries.