NEW YORK – A trio of Norman Rockwell paintings that for years resided in a New England museum named for him is being auctioned.

Saying Grace, The Gossips, and Walking to Church are among seven works by the Saturday Evening Post illustrator at Sotheby’s sale on Dec. 4.

For nearly two decades all three had been on loan at the Norman Rockwell Museum in Stockbridge, Mass., which has the world’s largest collection of original Rockwell art located in the artist’s hometown.

Saying Grace could set a new auction record for the American artist, Sotheby’s said. The painting, which depicts a crowded restaurant with a boy and woman bowed in prayer at their table, has a pre-sale estimate of $15 million to $20 million. In 2006, Sotheby’s sold Rockwell’s Breaking Home Ties for $15.4 million, the current record.

Rockwell was paid $3,500 for Saying Grace. It appeared on the cover of the magazine’s Thanksgiving issue in 1951 and was voted Post readers’ favorite cover in a 1955 poll.

The idea for the illustration came from a reader who saw a Mennonite family praying in a restaurant. Rockwell’s son, Jarvis, was among the models the artist used for the drawing.

The illustrator, who created his first cover for the Post in 1916, is celebrated for his reflections of small-town America and portraits of famous figures. Rockwell spent 47 years at the magazine and produced 321 covers. He died in 1978.

Gossips, which was a cover illustration for the March 6, 1948, issue, is estimated to bring $6 million to $9 million. It depicts a montage of the artist’s neighbors, his wife Mary and Rockwell himself finger-wagging and yammering on the phone.

Walking to Church could fetch $3 million to $5 million. It appeared on the cover of the April 4, 1953, issue and shows a family dressed in their Sunday best walking along a city street. Rockwell based it on a painting by Johann Vermeer.

All seven Rockwell works are being sold by the family of Kenneth Stuart, Rockwell’s longtime art director at the magazine. The sale comes years after a legal battle over the works among Stuart’s three sons. Rockwell and Stuart worked together at the magazine for 18 years.

Laurie Norton Moffatt, the Director at the Rockwell museum, has expressed hope that the three Rockwells will eventually be returned. “We cared for them like children. … We hope they come back some day. We believe that’s where they belong,” she said.

– Ula Ilnytzky