July 26 (Reuters) - Duolingo Inc said on Monday it had raised the price target range for its initial public offering in the United States, in a sign there is high investor appetite for shares of the language learning app. The company said nearly 5.1 million shares will now be sold in the IPO at a price range between $95 and $100 each. It had previously set the range at $85 to $95 per share. Duolingo could raise up to $511 million in the IPO, and on a fully diluted basis, the company"s value would be over $4.6 billion at the high end of the range. About 1.4 million shares would be sold by stockholders, proceeds from which would not go to the company. With more than 500 million downloads, the Duolingo app is the top-grosser in the education category on both Google Play and Apple"s App Store. The Pittsburgh-based company has about 40 million monthly active users learning 40 languages, including Irish and Hawaiian, for which the company claims there are more online learners than there are native speakers. Goldman Sachs & Co and Allen & Company are the lead underwriters for the IPO. The company plans to list on Nasdaq under the symbol "DUOL".