NEW YORK — Mattel’s American Girl dolls will soon be sold at Toys R Us stores, a major expansion for the toy company’s brand of pricey dolls.

The dolls are now sold at American Girl’s 20 stores and on its website. Making the dolls available in more places could help Mattel Inc. reverse the brand’s declining sales. Last year, American Girl sales fell 8 percent from the year before.

Starting in September, Toys R Us will sell American Girl’s new line of $60 WellieWisher dolls at all of its 870 U.S. stores. A month later, Toys R Us will open American Girl shops within about 100 of its stores. Those shops will sell the WellieWisher line and American Girl’s signature Truly Me dolls, which cost more than $100.

Mattel said it will be the first time the Truly Me dolls have been sold at a U.S. retailer outside of its own stores.

In a note to clients Wednesday, Jefferies analyst Trevor Young said the deal “bodes well” for an American Girl turnaround. Young expects sales of the brand to rise by the end of the year or early next year.

Mattel, based in El Segundo, California, said it plans to work with Toys R Us to open more American Girl shops in 2017.