Bookseller Waterstone’s is experimenting with selling more non-book products as it seeks alternative revenues in the face of a declining books market.

The bookseller – which has been put up for sale by its owner HMV – has kicked off a trial in a handful of stores this month.

Sources close to the situation said Waterstone’s wants to ramp up its children’s offer and has devoted more space to the category, which includes games and toys as well as books. It is also giving more space to its ‘paper’ offer , which includes notebooks, diaries and greetings cards, while introducing a seasonal category for celebrations such as Easter.

A source close to the situation called the changes “significant”.

Waterstone’s is the last man standing of the bookselling multiples after Borders collapsed in 2009.

HMV is trying to sell Waterstone’s for about £70m to pay off debt.

It is understood HMV received a £43m cash offer from Russian billionaire Alexander Mamut, but as Retail Weekwent to press no deal had been done with any party.

Waterstone’s declined to comment.