SALT LAKE CITY (AP) _ Spencer W. Kimball, the late president of the Mormon Church, was eulogized today by his heir apparent as a dedicated servant of God.

Kimball ''now takes his place alongside other apostles and prophets of this and other dispensations who have passed on to the other side of the veil. He will work even more actively there for the building of the kingdom of God on earth,'' Ezra Taft Benson said in remarks prepared for today's funeral service.

Benson, 86, former agriculture secretary in President Eisenhower's Cabinet, was to preside over the funeral, which was to be beamed via satellite to more than 1,000 Mormon chapels throughout the United States and Canada. Kimball was to be buried in the Salt Lake City Cemetery.

About 40,000 mourners filed past Kimball's open casket on Friday, so many that church officials extended viewing for another hour.

''Even though I've never met him, I feel like I know him,'' Cherie Campbell said Friday as she stood in an orderly line of mourners waiting to enter the Church Administration Building, where the body lay. ''I feel like he's my friend.''

Her sister, Sarah Snow, said she had met Kimball. ''It's kind of special to pay a last tribute,'' she said.

Kimball, the 12th ''prophet, seer and revelator'' in the 155-year history of the Church of Jesus Christ of Latter-day Saints, died Tuesday at the age of 90.

On Friday, many mourners expressed respect and affection for the late president, known for his gentle demeanor.

Church spokesman Don LeFevre said the line of those wishing to pay last respects was so long that viewing was extended for an hour until 10 p.m. MST.

''It's nice they opened it to everyone, not just the family,'' said mourner Debbi Thomas. ''He was my favorite. I'd go anywhere to say goodbye to him.''

LeFevre said the church's governing body, the Council of the Twelve, was expected to act quickly to formally select Benson to succeed Kimball, perhaps as soon as Sunday.

Benson was ordained an apostle, as council members are known, the same day as Kimball. As senior member of the council, he is believed by Mormons to have been picked by God to preside over the 5.8 million-member church.

The senior apostle has become president throughout the church's 155-year history and elevation of the politically conservative Benson is certain ''unless it is revealed to him that someone else should head the church,'' said another church spokesman, Jerry Cahill.

In the 19th century, years frequently elapsed before a successor to the president was chosen.

After the death in 1844 of Joseph Smith, who founded the church in 1830, the council governed for 31/2 years until it chose Brigham Young as president.