Founder and chairman of Alibaba Group Holding Ltd. Jack Ma, and vice chairman Joe Tsai on Monday said they would use their own money to buy Alibaba shares as the company began a two-year plan to buy back shares worth $4 billion.

China's biggest e-commerce company, however, did not disclose, in its filing to the New York Stock Exchange, how much the two will invest in the buyback as affiliated purchasers.

Currently Jack Ma owns 7.6 percent of Alibaba and Joe Tsai owns 3.1 percent.

The repurchase plan failed to significantly boost Alibaba's share price. Its shares rose 0.08 percent to $74.82 at 9.56 a.m. local time in New York, sightly higher than its IPO price of $68.

The Hangzhou-based company was listed on the New York Stock Exchange in September last year. Amid expectations of weaker growth, its shares have fallen from its all-time high of $120 in November.

Alibaba on Wednesday, when it first revealed the company's share repurchase plan, posted slower-than-expected revenue growth of 28 percent to reach 20.2 billion yuan ($3.2 billion) in the second quarter of the year.

The growth represents a slowdown from 40 percent in the fourth quarter of last year, and 45 percent in the first quarter of this year, as a slowing economy dragged down consumer spending.

(Xinhua News Agency August 17, 2015)