LOS ANGELES — After much prayer and deliberation, the nation's Roman Catholic bishops this week overwhelmingly approved a new English translation for the Mass that will change prayers recited by tens of millions of American Catholics for more than three decades.

The 173-29 vote of the U.S. Conference of Catholic Bishops, meeting here for its spring session, means that American Catholics will soon have to learn slightly different versions of texts that have become second-nature.

Bishop Donald Trautman, chairman of the conference's Committee on the Liturgy, called the decision "the most significant liturgical action to come before the policy-making body" in years.

"It will take some adapting, but it is not earth-shattering when you think of the changes we went through 40 years ago (when the Latin Mass was replaced by English in the United States)," said the bishop from Erie, Pa.

The alterations, which must be approved by the Vatican, also will affect the Penitential Rite. The current line, "I have sinned through my fault," will become "I have sinned greatly ... through my fault, through my fault, through my most grievous fault."

Prepared by the Vatican-appointed International Commission on English in the Liturgy, which translates the Mass for English-speaking countries, the new translation also include changes to the Nicene Creed, the Sanctus and Holy Communion.

The new translation conforms to recent Vatican rules designed to make liturgy more accurately reflect the original Latin of the Roman Missal.

Thus far, the new English translation has been adopted by bishops conferences of England, Scotland, Australia and Wales.