Amazon has quietly purchased the Australian-based e-commerce platform Selz, which enables businesses to build their own online stores.

The deal, terms of which were not disclosed, was made last month and confirmed by Selz in a blog post. The U.S. media reported the acquisition on Tuesday.

Selz's operations could help Amazon fend off challenges from the fast-growing Canadian-based firm Shopify, which offers a similar service to retailers.

Martin Rushe, founder and chief executive of Selz, said in the blog that the company had "signed an agreement to be acquired by Amazon and are looking forward to working with them as we continue to build easy-to-use tools for entrepreneurs."

Contacted by AFP, Amazon confirmed the acquisition but declined to comment on any future plans for the platform.

The deal comes with Amazon under heightened scrutiny from antitrust enforcers around the world for its growing role in online shopping.

The company has argued that it does not play a dominant role in overall retail sales despite its large share of online sales in the U.S. and other markets.

(Cover: VCG)