Britain's biggest sportswear retailer, Sports Direct confirmed it was mulling a possible cash offer for struggling outdoor goods retailer Blacks Leisure but warned there was no certainty any takeover would take place.

Blacks Leisure, whose largest shareholder is Sports Direct, said in a statement earlier on Tuesday that it had received an expression of interest from Sports Direct among a number of others, which may lead to an offer for the company.

Blacks put itself up for sale last week and warned investors the value of their shares could be wiped out in any deal.

Sports Direct, controlled by Newcastle United soccer club owner Mike Ashley, lifted its stake in Blacks Leisure to 22.48 percent from 21.3 percent last week.

Ashley has considered bidding for Blacks, and a report in the Financial Times said he had proposed a joint venture with the firm as an alternative to supporting an equity raising.

In response to the statement from Blacks, Sports Direct said: At this stage, there can be no certainty that Sports Direct will make an offer for Blacks Leisure, nor as to the terms on which any such offer might be made.

The company added that in the event of any offer, it was likely to be in cash.

(Reporting by Lorraine Turner; Editing by Helen Massy-Beresford)