* To unveil new Wii at E3 game show in June
* Wii console sales fall to 15.1 mln units from 20.1 mln
* Oper profit tumbles 52 pct to 171.1 bln yen in year to March
* Profit below 200.8 bln yen SmartEstimate
* Sees op profit of 175 bln yen for yr to March 2012; consensus 215.8 bln yen (Adds quotes, detail)
By Isabel Reynolds
OSAKA, Japan, April 25 (Reuters) - Nintendo Co Ltd will launch a successor to its Wii game console in 2012 as it seeks a new hit games platform to reverse a fall in profits after seeing users lured away by rivals Microsoft and Sony .
The maker of the DS handheld games, which is battling a fall in sales and profits, said it will unveil a prototype of the new Wii in Los Angeles on June 7 at the E3 game show.
"As for the details of exactly what it will be, we have decided that it is best to let people experience it for themselves at E3," Nintendo CEO Satoru Iwata, told a news conference on Monday.
"So I won't talk about specific details today, but it will offer a new way of playing games within the home," said Iwata, a former game designer.
Nintendo also reported its second straight fall in annual profit, as demand for Wii games console, which has sold 86 million units since launching in 2006, slowed and the March 11 earthquake curbed Japanese consumer spending.
Intent on catching up with Nintendo, Microsoft and Sony have since brought new products to the market to take on their more successful competitor.
To fend of increased competition from other game console makers and makers of smartphones including Apple Inc Nintendo launched a glasses-free 3D-capable handheld games device, the 3DS, this year.
In the business year just ended, Wii console sales fell to 15.1 million units from 20.1 million a year earlier. It expects sales to fall by a further 2 million units this business year.
Sales of its non-3D handheld DS shrank by almost 10 million units to 17.5 million, and the company expects that to slide to 11 million this term.
Nintendo' operating profit fell 52 percent to 171.1 billion yen ($2.09 billion) in the year ended in March from 356.8 billion yen the previous year, below a Thomson Reuters SmartEstimate of 200.8 billion yen.
SmartEstimates put more weight on recent forecasts by highly rated analysts.
Nintendo expects operating profit of 175 billion yen for the year to March 2012, compared with a consensus of 215.8 billion yen, based on eight analysts polled by Thomson Reuters I/B/E/S after the March 11 disaster.
Nintendo shares closed up 0.9 percent ahead of the earnings report in a flat broader market . ($1 = 81.845 Japanese Yen) (Writing by Anshuman Daga; Editing by Lincoln Feast)