Mattel's brands include the iconic Barbie doll, Hot Wheels and Matchbox cars, Fisher-Price toys and American Girl dolls.
Representatives for Hasbro and Mattel declined comment on the report, saying they don't respond to speculation.
The approach was made recently, the WSJ said, citing one person.
Mattel Inc. (MAT) shares soared more than 20% in the extended session Friday following a report that Hasbro Inc.
A new report claims that Hasbro Inc. has made a takeover offer for its rival, Mattel Inc., although details surrounding the offer are now unknown.
Hasbro, based in Pawtucket, R.I., makes toys such as Transformers, G.I. Joe figures, My Little Pony, Nerf and Play-Doh, and games including Monopoly, Scrabble and Twister. Last month the company suspended its dividend and warned it would miss forecasts for revenue this year. But Mattel's shares are down by almost half this year alone - an appealing discount for Hasbro.
"We believe its brands and manufacturing footprint could be worth more than $10 billion in their current state", analyst Gerrick Johnson of BMO Capital Markets said in a note to clients. Shares of Hasbro rose 3.6% to $94.70 after hours. Shares of Mattel have dropped by 47% during the year, valuing the business at just over $4.8 billion and making it a target for a takeover.
Mattel and Hasbro have held talks a number of times in the past, including as long ago as 1996 and as recently as late in 2015.