Struggling British sportswear retailer JJB Sports said investors including Bill Gates, the United States' richest man, have backed a 31.5 million pounds ($48.57 million) fundraising to keep the firm alive, according to Reuters. JJB said on Friday the Bill and Melinda Gates Foundation Trust, which holds a 5.5 percent stake, had agreed to support a capital raising at 5 pence a share -- a 25 percent premium to Wednesday's closing price -- along with JJB's other main investors Harris Associates, Crystal Amber and GoldenPeaks Capital. The four together hold 44.3 percent of JJB shares. JJB shares, which prior to Friday had lost 83 percent of their value over the last year, were up 23 percent at 5.25 pence at 1043 GMT, valuing the business at 34 million pounds. The retailer, which issued a profit warning in November, said its main lender Bank of Scotland had agreed to waive covenant tests for the firm's 25 million pounds facility on the basis of the proposed capital raising. The company had warned earlier this month it was likely to breach the covenant. JJB also shook up its board, with chairman John Clare and chief financial officer Lawrence Coppock stepping down to be replaced by Mike McTighe, a former Cable & Wireless executive and restructuring expert, and Dave Williams, former finance director of discount retailer TJ Hughes. Gates, the billionaire philanthropist and founder of Microsoft, is no stranger to British retail laggards. He has built up a significant holding in Carpetright, the nation's biggest floor coverings retailer which earlier this month posted a 28 percent fall in first-half profit. News of JJB's funding lifeline offset news of dire pre-Christmas trading, with sales at stores open over a year slumping 15.7 percent in the six weeks to Dec. 19. JJB blamed the fall on the extreme winter weather and "stock availability issues." Gross margin fell 9.9 percentage points year-on-year. Analysts were also alarmed by JJB's warning that the proposed fundraising will not address its medium and longer term working capital requirements. "We remain sellers of the shares, with the theoretical upside from a recovery being further diluted and the likelihood of further, larger, fundraisings required in the New Year," said analysts at Altium Securities. JJB was driven to the brink of administration during the recession, but survived thanks to a deal to sell its fitness clubs to founder Dave Whelan, a debt restructuring with creditors, new banking facilities and an equity fundraising. Under new chief executive Keith Jones it has since been refitting stores and improving its internet business within a strategy targeted at keen amateurs, recreational sports participants and sporting families. But analysts believe the group has suffered recently from a step-up in promotions and advertising from market leader Sports Direct, which is controlled by Newcastle United soccer club owner Mike Ashley.