The troubled retailer said it has agreed the deal for up to £13.5 million in a move to help slash its debt pile.
The Early Learning Centre (ELC) is run within 80 Mothercare stores in the UK, 400 stores internationally via franchise partners, and online.
The acquisition also includes ELC’s portfolio of toy brands, such as Happyland.
But Mothercare will retain around £6 million of Early Learning Centre stock to sell down.
It said the move will help it pay off around £17.5 million of debt over the next year, while it has also struck an “arm’s length” concession deal with The Entertainer for the supply of toys to stores and online.
Mothercare, which is overhauling the business to boost its flagging fortunes, added that its swingeing store closure plan was ahead of schedule, with 57 stores set to shut by the end of March, taking its estate down to 80 from 137 last May.
Chief executive Mark Newton-Jones said: “We have made significant progress in recent months as we continue our strategic transformation to deliver a sustainable and profitable future for Mothercare.
“This disposal of Early Learning Centre provides a further step towards eliminating our bank debt, and our new concession arrangements with The Entertainer will bring our customers an even stronger toys offer, both in stores and online.”
The group said the ELC deal comes as it lacks the scale and resources to develop the toy ranges, amid an “intensely competitive” market.