Toymaker Mattel Inc. has agreed to purchase Montreal-based Mega Brands Inc., seller of children’s building blocks, for about $460 million including the assumption of debt.

Mega Brands’ line of Mega Bloks construction toys is considered a direct competitor to Danish building toy behemoth Lego Group.

El Segundo-based Mattel, known for its Barbie dolls and Hot Wheels toys, said the purchase will allow it to expand into construction sets and arts and craft toys. It has plans to keep Mega Brands’ head office in Montreal.

Mattel’s shares were trading slightly higher midday, up less than 1 percent to $37.38.