Online retailer Inc introduced a plan on Wednesday to offer authors and publishers a bigger cut of the discount books sold on its popular Kindle electronic reader.

Under the new program, which goes into effect on June 30, authors and publishers will get 70 percent of a book's list price, net of delivery costs. The plan is limited to books whose list price is between $2.99 and $9.99.

The higher royalty program is also restricted to books whose list price is at least 20 percent below the lowest listed price for the physical book, Amazon said.

The Kindle e-reader, introduced in 2007, has been a top selling item for Amazon. But it faces pressure from Barnes & Noble Inc and Sony Corp's rival e-readers.

Authors typically get between 7 percent and 15 percent of the list price for their physical books, or 25 percent of the net proceeds publishers get for their digital books, Russ Grandinetti, vice president of Kindle Content, said in a statement.

The statement did not specify what the current royalty rates are for books targeted by Amazon's new program.