Borders Group Inc is set to close another 28 of its superstores on top of the 200 locations it is already shutting down as part of its reorganization under bankruptcy protection.

Those locations will close by the end of April and include stores in Hollywood, California, and Stamford, Connecticut. The closings will leave Borders with only half of its superstores.

We reached the determination about these stores after a further review of their ongoing economic viability, Borders spokeswoman Mary Davis said in a statement.

Borders, the second-largest U.S. bookstore chain after Barnes & Noble , filed for bankruptcy protection last month, several weeks after it delayed payments to some publishers, a number of which in turn stopped shipping books.

Borders is receiving shipments from most of its largest vendors on cash-on-delivery terms, and hopes to resume getting books shipments under regular terms soon, Davis said.

Borders, which aims to emerge from bankruptcy protection by September, was given more time on Tuesday to negotiate store leases and decide which ones it will reject.

Before the bankruptcy filing, Borders operated more than 500 namesake superstores, as well as the Waldenbooks chain of smaller bookstores.

The case is In re: Borders Group Inc, U.S. Bankruptcy Court, Southern District of New York, No: 11-10614.

(Editing by Steve Orlofsky)