NEW YORK — Starbucks announced on Thursday that it is buying the remaining 50 percent share of its East China joint venture in a $1.3 billion transaction, marking the largest single acquisition ever in the company history.

The Seattle-based coffee chain will assume 100 percent ownership of about 1,300 stores in Shanghai, Jiangsu and Zhejiang after it acquires the rest of share from its business partners Uni-President Enterprises Corporation and President Chain Store Corporation, according to a statement Thursday.

China is the company's fastest-growing market outside of the United States in terms of store count and the acquisition builds on the company's ongoing investment in the country.

In the statement, Starbucks reaffirms its commitment to operating 5,000 stores on the Chinese mainland by 2021.

Shares of Starbucks rose 1.72 percent to 58.94 dollars apiece in intraday trading Thursday after the news came out.

East China is a significant and strategic region for Starbucks, with Shanghai containing nearly 600 stores, the largest number of stores globally of any city where Starbucks has a presence.

In December 2017, Shanghai will also be the first city outside of the United States to open the brand's high-end Roastery.