* Modi arrives in New York Thursday, West Coast at weekend
* Big rally, meeting with tech titans planned
* Hopes to nurture India's burgeoning startup scene
* Stalled nuclear deal, economic reforms take shine off
By Frank Jack Daniel
NEW DELHI, Sept 23 (Reuters) - Tech titans will court Indian Prime Minister Narendra Modi in Silicon Valley this weekend, but away from the glitz, the euphoria of his first trip to the United States a year ago has faded as promised deals stall and key reforms flounder.
A firm believer in the new economy and power of social media, Modi will be welcomed by Apple, Facebook and Google, who want to grow in a market where the world's third-largest internet user base is set to multiply in coming years.
Apple CEO Tim Cook is due to drop by Modi's hotel in San Jose, before the Indian leader joins Mark Zuckerberg for a "townhall" session broadcast live from Facebook headquarters.
He will be able to relive some of the glory of 2014's rock star-like Madison Square Garden rally in New York when he addresses 17,000 Indian expatriates at San Jose's "Shark Tank" sports arena on Sunday.
Modi's standing in the United States rose further when U.S. President Barack Obama visited India in January and the two tightened defence and civil nuclear cooperation with a promise of billions of dollars of business.
The relationship is still evolving, with the world's two biggest democracies agreeing on Tuesday to jointly train peacekeepers in Africa, a step in a growing military alignment partly aimed at balancing China's expansion.
But in other areas, progress has been slow.
Western businesses and diplomats in Delhi privately say Modi's reputation as a man of action has been hurt by setbacks on economic reform. Some carp that he is better at speeches and launching projects than seeing them through.
The Thomson Reuters/INSEAD Q3 Asian Business Sentiment Survey found on Wednesday that optimism among Indian companies, while still high, had been dented by the slow pace of reform.
U.S. lawmakers wrote to the Obama administration on Monday complaining about barriers to trade they said had got worse under Modi, as well as disputes over copyrights and patents.
"The sheen is off, certainly. He is no longer the new kid on the block," said Neelam Deo, a former Indian diplomat in Washington now at Gateway House, a think-tank.
"The first trip was euphoric, this one is much more a consolidation phase of the relationship."
CHOPPER RED TAPE
On Tuesday, India's cabinet approved a $2.5 billion purchase of 37 Apache and Chinook helicopters from Boeing, giving Modi something concrete for when he meets Obama on Monday.