Online book retailing is about to get a little bit less competitive, with Amazon announcing that it will buy The Book Depository.

The cost of the transaction remains undisclosed.

The Book Depository tries to reassure its customers, saying its service will improve.

The British company, which is popular in Australia due to its low prices and free shipping, was expected to chalk up sales of £120 million ($180 million) for the fiscal year ending in June, according to industry specialist TheBookseller.com. Last year it had an operating profit of £2.3 million, TheBookseller.com said.

On its website, the company sought to reassure its customers that its service and range would improve after the acquisition by Amazon.