Russian oligarch Alexander Mamut has increased his stake in HMV again, to more than 6%.

Speculation is continuing to mount that Mamut may see an opportunity for linking HMV to Russian mobiles business Yevroset, in which he holds a 50.1% stake.

Last month he raised his stake to 5%.

The struggling entertainment retailer last week warned on profits and cautioned that it could break its banking covenants after poor Christmas trading.

Mamut was also formerly an investor in now defunct Russian bookseller Bookberry, along with Tim Waterstone, founder of the eponymous books chain that it now part of HMV.

As part of HMV’s turnaround plan, it plans to shed 60 stores across the eponymous entertainment chain as well as its bookseller Waterstone’s. According g to the Financial Times, retailers including Apple, Hollister, TK Maxx and Poundland have expressed interest in some of the shops.