The German competition regulator is looking at the way sportswear companies restrict the distribution of their products, especially over the internet, following complaints about moves to limit sales to authorised retailers.

The investigation has been prompted by Japanese athletic footwear and apparel company Asics, which is in the process of rolling out its 'Selective Distribution Policy' throughout Europe.

"Under this policy, Asics selects its authorised retailers on the basis of pre-defined criteria which every authorised retailer must meet in order to sell Asics products going forward," the company told just-style.

A separate statement from the Bundeskartellamt, the German competition regulator, said it was simply checking Asics' new delivery conditions rather than launching a blanket "investigation" against brand manufacturers.

However, it said several complaints have also been made by retailers against Adidas and Nike, although no probes are currently underway.

"We have a range of complaints from traders - also regarding the planned changes at Adidas," the statement said. "In this context, we are currently conducting an investigation for the delivery of the rules changes at Asics. Restrictions also play a role in online sales."

Asics said it wants to "ensure that the distribution meets the high requirements of the Asics products and the Asics brand image" including the shopping environment, product variety, product information, after-sales service and interaction with the consumer.

Adidas said it has been "following this strategy for several seasons now. As part of the implementation of this strategy we are regularly analysing and differentiating our distribution channels across Europe. Our new e-commerce guidelines will ensure that Adidas and Reebok will be presented in the right environment at all times."

Nike also told just-style it has a selective distribution policy in place in Europe under which it only appoints authorised retailers to sell Nike products.

"To be an authorised retailer you have to meet particular terms of sales and competencies. This model helps guarantee that consumers can be sure that all the products purchased online are genuine and meet all the requirements regarding the quality and customer service."