Bankrupt bookseller Borders Group Inc has so far failed to find a bidder for the entire chain, Bloomberg reported, citing four people close to the matter.

Larger rival, Barnes and Noble Inc offered to buy about 10 stores and other parties also bid for parts of the business, but the company has not been able to find a buyer for a larger piece of the chain, Bloomberg's sources said.

The deadline for so-called going-concern bids that would keep the company operating was May 6, according to Bloomberg.

Borders Group Inc, which helped pioneer the concept of book superstores, stocking more than 100,000 titles, filed for bankruptcy protection in February after years of shriveling sales that made it impossible to manage its debt load.

We are focused on moving forward with the execution of our business plan, Mary Davis, a Borders spokeswoman, told Bloomberg. We are continuing to evaluate interest in the company as expressed through the ongoing Chapter 11 process.

Reuters could not immediately reach Borders for a comment.

(Reporting by Siddharth Cavale in Bangalore; Editing by Carol Bishopric)