A group of activist shareholders on Monday called on Rentech Inc. to postpone any new stock offerings or other capital raising efforts until after the company’s annual meeting.

The shareholders, organized under the name Concerned Rentech Shareholders, said the company’s board and management squandered shareholder money on a succession of product initiatives that didn’t pan out.

Rentech this month sold its biofuel business to a Chinese company so that it could focus on its wood chip, wood pellet and nitrogen fertilizer manufacturing businesses.

The company last week reported a larger-than expected fiscal fourth-quarter loss. During the fourth quarter conference call, the company said it eventually wanted to spin off the wood products units into a separate public company, as it had successfully done with the nitrogen fertilizer business. But management said it likely would have to spend at least $100 million in the near-term to grow the business to a size where an initial public offering would be viable.

The activist shareholders, led by fifth largest shareholder Engaged Capital of Newport Beach, said in a letter to the board dated Monday that they lacked confidence in the current management team.

“The board and management’s poor capital allocation and execution track record warrant no confidence that they can successfully execute on any initiatives,” the group said.

Rentech has not yet commented on the letter, which is the second the group has sent to the company and made public in the last two months. The first letter laid out similar concerns. The company had responded to the first letter by saying that executives were making their best efforts and that they wanted to meet with the shareholders.

In the most recent letter, the activist shareholder group claimed that the company wasn’t flexibile enough in scheduling a meeting.

Rentech shares closed up 6 cents, or 3 percent, to $1.85 on the Nasdaq. Its majority owned Rentech Nitrogen Partners closed up 7 cents, or less than 1 percent, to $17.92 on the New York Stock Exchange.