Adds share moves in paragraph 2, more details in paragraphs 4 and 6, context over Brazilian e-commerce segment in paragraph 5

SAO PAULO, Nov 18 (Reuters) - Brazilian retailers Magazine Luiza MGLU3.SA and Americanas AMER3.SA announced an e-commerce partnership on Tuesday and will each start selling their products on the other's respective retail platform.

Shares in Magazine Luiza were up 3% in the afternoon, while Americanas rose more than 5%. Brazil's equity benchmark index Bovespa .BVSP, which Americanas is not part of, was stable.

Americanas will begin to sell its products on Magazine Luiza's e-commerce platform from Tuesday, while Magazine Luiza will do the same on Americanas' platform in the next few weeks, the firms said in a joint statement.

The deal is the latest of retailers joining forces in Brazil's e-commerce segment, which has seen an increasingly competitive environment this year as players, including Sea's SE.N Shopee, Amazon AMZN.O and MercadoLibre MELI.O, expanded free-shipping policies and offered consistent promotions.

MercadoLibre announced a partnership last month to sell Brazilian retailer Casas Bahia's BHIA3.SA products on its platform. Magazine Luiza itself has had an e-commerce partnership with China's AliExpress in Brazil since 2024.

Magazine Luiza and Americanas said they have a complementary portfolio, given Magazine Luiza's strength in electronics, household appliances and cell phones, and Americanas' operations in snacks, cleaning products and personal hygiene.

(Reporting by Andre Romani; Editing by Brendan O'Boyle and Kylie Madry)

((Andre.Romani@thomsonreuters.com; 11 991314109;11 56447500;))