(Adds details on Ackman, shares)
Feb 28 (Reuters) - Herbalife Ltd said on Wednesday it plans to change its corporate name, refinance debt and effect a 2-for-1 stock split to boost shareholder returns, sending its shares to an all-time high.
The nutritional supplement maker also said it intends to launch a "modified Dutch auction" tender offer, seeking to repurchase between $450 million and up to $650 million of its outstanding common stock.
The moves come a few months after activist investor Bill Ackman bought options to sell shares as a new way to bet against the company, after closing a $1 billion short position he took in 2012.
For years, Ackman has labeled the company a pyramid scheme and said it will eventually crumble under regulatory scrutiny over its operating model, which he alleges benefits distributors more than the actual users of products.
Herbalife's shares have instead risen since Ackman made the $1 billion bet, forcing him to close that position and limit his losses through options to sell shares.
Ackman's hedge fund Pershing Square Capital Management was not immediately available to comment.
Herbalife said on Wednesday it intends to change its name to Herbalife Nutrition Ltd and would also refinance a portion of its $1.15 billion outstanding convertible notes due Aug. 15, 2019.
The forward stock split will be Herbalife's first in seven years and will double the number of outstanding shares, boosting liquidity.
The proposals to split its stock and change its name will be put to a vote at the company's Annual General Meeting on April 24. (Reporting by Vibhuti Sharma in Bengaluru Editing by Saumyadeb Chakrabarty)