IndiGo, India’s biggest and most-profitable airline, will sell its shares on the stock market in an initial public offering (IPO) valued at up to $500 million, as it seeks to retain control of the country’s highly competitive aviation market.

India has signed a contract with Slovenia-based Pipistrel Aircraft to buy 194 Virus SW80s and is likely to buy an additional 100 aircraft after three years.

India is planning to launch an advanced meteorological satellite in July 2016 to augment the country’s weather forecasting and disaster warning capabilities.