TIME Warner Inc's HBO cable network is expected to start selling shows on Apple Inc's iTunes digital entertainment service, with flexible pricing, sources familiar with the discussions said on Monday.

Episodes of some HBO shows are likely to be sold at the standard price of US$1.99 per episode or higher, these sources said, marking the first time Apple has agreed to sell TV shows at different prices in the United States.

Although some global iTunes stores, including Japan, already sell songs at different prices, Apple has resisted offering music or television shows at different prices for the sake of simplicity for consumers.

But studio and music company executives have pushed for variable pricing, such as the ability to sell some content at lower prices and new releases at higher prices, which they believe would improve sales from its older catalogs.

Apple's pricing structure also was part of the reason why General Electric's NBC Universal decided last year to pull its shows from iTunes.

The move marks the first time HBO has made its shows available for sale in electronic form.