(Adds detail) LISBON, Oct 29 (Reuters) - Portugal’s economy expanded 2.9% in the third quarter compared with the previous three months as the easing of most coronavirus rules allowed more businesses to reopen and spurred exports, data from the National Institute of Statistics (INE) showed on Friday. INE said that between July and September the country’s tourism-dependent economy grew by 4.2% from a year earlier. “The GDP growth in the third quarter reflects the gradual reduction of the restrictions to mobility imposed due to the pandemic, in line with the increase in vaccination against COVID-19,” INE said in a statement. Portugal has more than 85% of its population fully inoculated against the coronavirus, among the world’s most vaccinated nations. INE said net exports had “a positive contribution” to third quarter GDP, while domestic demand - investment and consumption - had a “less positive contribution than in the previous three months”. The tourism sector, which represented around 15% of GDP before the pandemic hit, is still suffering due to some rules making harder for people to travel. Portugal started to ease COVID-19 restrictions from mid-March after imposing its second lockdown in January to tackle what was then the world’s worst surge of infections. The government expects the economy to grow 4.8% this year. It shrank 8.4% in 2020, its biggest slump since 1936. (Reporting by Sergio Goncalves and Joao Manuel Mauricio Editing by Catarina Demony and Mark Potter)