Shares in Athens International Airport SA jumped 15 percent in early trading on the Athens Stock Exchange, marking the country’s largest initial public offering in more than two decades.

The shares began trading at 9.40 euros apiece, up from the IPO price of 8.20 euros, the top end of the initial range. While the ASE index rose 0.28%, reaching its highest level since May 2011.

Last week, the Greek state raised 785 million euros ($843 million) by selling its 30 percent stake in the 23-year-old airport known as Eleftherios Venizelos. Investor demand exceeded the amount offered within hours of the opening of trading. The IPO is just one of the latest signs that Greece’s economy, which outperformed most of its European peers last year, is back on track more than 10 years after the financial crisis.