(Corrects to Thursday from Wednesday in first paragraph)

Oct 27 (Reuters) - Chinese package delivery company ZTO Express's shares (ZTO.N) opened 5.6 percent below the IPO price in their market debut on Thursday.

Shanghai-based ZTO's offering is the biggest U.S. initial public offering of the year and the largest by a Chinese company since the $25 billion IPO of e-commerce giant Alibaba Group Holding Ltd (BABA.N) in 2014.

ZTO shares, which opened at $18.40, fell as much as 10 percent in morning trading.

ZTO's IPO of 72.1 million shares was priced at $19.50 per share, above the previously expected range of $16.50-$18.50 per share, to raise $1.41 billion.

The deal adds a much-needed boost to the volume of U.S. IPOs from Chinese firms, which plunged to just $309 million from five deals in 2015, after a record $29 billion in the previous year because of Alibaba's listing, according to Thomson Reuters data.

Chinese companies, particularly not-yet-profitable technology firms, had been flocking to U.S. markets for years, counting on a large pool of fund managers, which are more familiar with startup investing, to raise funds for expansion.

Founded in 2002, ZTO is a major player in China's quickly expanding e-commerce market. It delivers parcels for Alibaba and JD.com Inc (JD.O) , among others.

ZTO will use the proceeds from its offering to buy more trucks, expand capacity through the purchase of land, facilities and equipment, and for other general corporate purposes.

Sales of ZTO jumped to RMB 6.1 billion ($915.8 million) in 2015, up from RMB 3.9 billion in 2014. Its net income was RMB 1.3 billion ($200.4 million).

Morgan Stanley, Goldman Sachs Group Inc, China Renaissance, Citigroup Inc, Credit Suisse AG and JPMorgan Chase & Co are among underwriters for the listing.