US mobile operator Sprint Nextel is reportedly set to invest over US$100 million in promoting a new handset seen as a rival to the new 3G iPhone. Reuters reports that the operator will launch Samsung’s new ‘Instinct’ device on an exclusive basis from tomorrow. The reports adds that the US$100 million set aside to promote the handset is about three times the marketing budget of Sprint’s largest handset launch of last year.

The device is seen as a serious competitor to the new iPhone, which is being launched in the US on an exclusive basis by rival Sprint operator AT&T next month. Like the iPhone, Instinct uses touchscreen technology but Sprint will undercut AT&T on price by offering the device for US$130 on a two-year contract with a US$100 rebate by mail. AT&T plans to sell the iPhone for US$199. In other iPhone news this week, Australia’s largest mobile operator Telstra has been linked to the launch of the new iPhone in late July. Local rival operators Vodafone and Optus have previously announced that they will begin selling the iPhone on July 11, the day of its global launch, leaving Australia’s fourth-largest mobile network – Hutchison’s 3 – as potentially the only regional operator yet to announce an iPhone launch. Meanwhile, UK operator O2 has reportedly received 130,000 pre-registrations for the 3G iPhone, four times the interest for the original model.