Canadian fertilizer maker and agricultural goods retailer Agrium said on Monday its board plans to double the annual dividend payout.

The move, announced as the company completed a C$900 million ($908.4 million) share buyback, comes in the face of pressure from its largest shareholder, Jana Partners, which wants the company to explore options to boost shareholder value.

Jana has been pushing for a split of the Canadian fertilizer company's wholesale and retail division, but Agrium has stood its ground, arguing that its integrated business model benefits shareholders.

Agrium is a major producer of nitrogen fertilizers. It also produces potash- and phosphate-based nutrients used to boost crop yields. In addition, the company owns the biggest network of farm retail stores in the United States that sell seed, chemicals and fertilizer.

The Jana hedge fund, which owns about 4.0% of the Calgary, Alberta-based company, also wants Agrium to improve disclosure, reduce operating costs and working capital and address some corporate costs.

"The increased dividend and C$900 million substantial issuer bid are an indication of our confidence that our integrated business model will continue to deliver strong results for the benefit of shareholders," said Agrium Chief Executive Mike Wilson.

Agrium said it intends to double its dividend to $2 a share on an annualized basis and move to a quarterly payment schedule from a semi-annual payout, as of the next scheduled dividend in January.

The company said it bought back about 8.72 million shares for about C$103 a share as part of its repurchase plan, and the amount represents about 6% of the company's outstanding stock.