Last month, the company announced that the non-core or unprofitable parts of the business would be sold, closed or reorganised in an attempt to reach profitability.
The company has confirmed that Music365 will be one of those sites to be put up for sale. If a buyer is not found, however, the site is likely to be closed.
The move ends months of speculation in the press, which began when Music365 laid off staff in February. For the last six months, the site has been operating with a skeleton staff.
It is not known which other sites are under scrutiny, but finance director Martin Turner said the company would be monitoring those that are not market leaders. It has already closed its Gardening365 site, and merged its Business365 site into its Symphony subsidiary.
Last month, the company reported pre-tax losses of £45m for the year ending March 31, compared with £12.7m the previous year.