Wintergreen Advisers renewed its criticism of Coca-Cola's executive compensation plan on Tuesday, saying the company didn't do enough to inform shareholders about bonuses that can be awarded to management.

The investment fund said Coca-Cola Co.'s April 2014 proxy statement did not adequately explain the concept of bonus shares that can be awarded to company executives, and said the compensation committee of the board of directors did not tie the bonus shares to any company performance goals.

Wintergreen repeatedly called the awards "secret bonus shares" and said Coca-Cola's proxy statement "fell far short of both the spirit and the letter of the federal securities laws governing proxy disclosure."

Coca-Cola said the awards were not secret and were outlined in its regulatory disclosures.

"We utterly reject David Winters' erroneous accusations," the company said in an email.

Wintergreen said Coke should immediately claw back any shares that have been awarded, said it shouldn't award any more shares in the future, and that any executives and directors involved in the plan should quit.

In March Wintergreen said it objected to Coca-Cola's equity compensation plan, saying the plan would transfer about $13 billion in stock to Coca-Cola management over the next four years. Wintergreen CEO David Winters said that was a bad deal because of Coke's slowing growth. Warren Buffett, whose Berkshire Hathaway is the biggest shareholder in Coca-Cola, did not vote against the plan at the company's annual meeting but called it excessive.

Later in the year the Atlanta-based company made changes to the program, saying it would give out fewer shares to a smaller group of executives. Other executives will get cash bonuses.

Wintergreen owns about 2.5 million shares of Coca-Cola, which gives it a stake of less than 1 percent.

Shares of the company closed up 4 cents at $41.63.