SHANGHAI - China's top online travel agency Ctrip reported robust revenue growth in the third quarter of this year thanks to steady service expansion in domestic lower-tier cities and international markets.

The company raked in about 9.4 billion yuan ($1.4 billion) in net revenue in Q3, up 15 percent year-on-year, according to its unaudited financial report released Thursday.

Accommodation reservation and transportation ticketing were the two major revenue contributors, the report showed.

Jane Sun, Ctrip's CEO, attributed the company's solid Q3 financial performance to its large, growing and loyal customer base that is continuing to use the agency, China's largest online provider of a wide range of travel services including hotel reservations, transportation ticketing, packaged tours and corporate travel management.

In Q3, Ctrip benefited from its expanded presence in third- and fourth-tier cities in China, with the total gross merchandise volume of its 7,000-plus offline stores surging over 80 percent year on year during the July-September period.

Skyscanner, the British price comparison travel search site bought by Ctrip in 2016, grew about 250 percent year-on-year in revenue thanks to the booming direct booking business. Excluding Skyscanner, Ctrip's international air businesses expanded 30 percent year on year, almost tripling the average industry growth rate, according to the report.

"We will continue to work hard to extend the advantages of scale, while seizing the opportunities presented by globalization to drive Ctrip's long-term success," said James Liang, the Shanghai-based company's executive chairman.

Chinese people made about 1.3 billion overseas trips in 2017. International market consulting firm McKinsey predicted an annual growth rate of six percent for China's overseas trips and total spending by 2020.

Ctrip said about 70 percent of its users are aged under 35 years old, while the ratio of users under 29 has risen from 30 percent to about 50 percent in the past five years.

Liang is upbeat about the tourism market's future due to his confidence in China's long-term economic growth, given the huge potential for improving the country's per capita GDP and urbanization rate.

In Q3, the company rolled out a tailored service to cater to domestic tourism spending in destinations along the country's high-speed railways, and an innovative solution to help users reduce train ticket costs in the UK.

Ctrip expects its net revenue growth to continue at a year-on-year rate of approximately 15 to 20 percent in the fourth quarter.