Herbalife announced early Monday it is increasing its share buyback program by $500 million, to $1.5 billion. The buyback is being financed by selling $1 billion of convertible bonds.

It’s the latest effort by the downtown Los Angeles nutritional supplement company to reward shareholders after Herbalife’s business practices were called into question last year by activist investor Bill Ackman. Ackman made a $1 billion bet that the company’s share price would fall, but instead shares rose 81 percent in the past year.

Herbalife also said net income for its quarter ended Dec. 31 will exceed analyst expectations, but that net income for the first quarter of this year will likely fall short.

Herbalife said that in addition to paying for the buyback, proceeds from the bond sale will go toward general corporate purposes.

Shares rose 6.6 percent Monday on the New York Stock Exchange to close at $68.59, and continued to rise in after-hours trading.