By Aditya Kalra, Aditi Shah and Anirban Sen.: NEW DELHI (Reuters) - Indian content-sharing platform ShareChat is in early-stage talks with U.S.-based Sequoia Capital and some other investors to raise up to $200 million, which could value the company at over $1 billion, three sources aware of the matter told Reuters. ShareChat has appointed JPMorgan to advise on the new fund raising which it expects to complete before the end of the year, said the sources, who declined to be named as the talks were private.