* Q3 revenue seen in $8.12-$8.22 bln range vs $7.06 bln in Q2
* Says to offer guidance in US$ to smoothen currency effect
* Q2 net profit T$66.27 bln vs T$68.44 bln forecast of analysts (Adds company comments, details)
By Jess Macy Yu
TAIPEI, July 13 (Reuters) - Taiwan Semiconductor Manufacturing, the world's largest contract chipmaker and a key Apple supplier, forecast third-quarter revenue to rise after a traditionally weak second quarter that was also hit by unfavourable currency moves.
Taiwan's most valuable company said that new gadget launches in the second half, particularly smartphones, will help boost its revenue for the quarter ending in September by at least 15 percent versus the June quarter, which suffered from the appreciation of the Taiwanese currency against the U.S. dollar.
"Almost 100 percent of our revenue is in US dollars...In the last two quarters, the appreciation has had a very big impact on our revenue," Chief Financial Officer Lora Ho told reporters on Thursday.
TSMC, which has a market capitalisation that exceeds Intel Corp's, said revenue for the July-September quarter will be between $8.12 billion and $8.22 billion, compared to the $7.06 billion posted for the April-June quarter.
TSMC and its rivals are riding a boom in demand for chips that power smartphones and computer servers, driving sharp gains in their shares. South Korea's Samsung Electronics Co last week estimated a record quarterly operating profit for April-June.
Apple is gearing up to launch its 10th anniversary iPhone, and analysts expect TSMC and some other suppliers to benefit from it.
TSMC's revenue forecast came as its second-quarter net profit fell 8.6 percent to T$66.27 billion ($2.19 billion) from T$72.51 billion in the year-ago quarter. That compared to the T$68.44 billion average forecast of 22 analysts, according to Thomson Reuters.
The company said that from this quarter it will offer revenue guidance in U.S. dollar terms, a departure from denoting it in Taiwan dollars. Revenue in U.S. dollars fell 5.9 percent in the second quarter from the previous quarter, but was up 3.2 percent from a year ago, it said. ($1 = 30.2730 Taiwan dollars) (Reporting by Jess Macy Yu and J.R. Wu; Editing by Muralikumar Anantharaman)