Options include building a C$775 million ($580.61 million) terminal at Prince Rupert, British Columbia, which would allow Canpotex to bypass busy Port Metro Vancouver and cut shipping times to China by two days, said CEO Ken Seitz, in an phone interview from Saskatoon, Saskatchewan.

"We never want ports to be the bottleneck, so we need sufficient capacity," Seitz, 46, said. "If we take a long-term view, we believe that to properly position ourselves, we'll need more port capacity somewhere."

Canpotex, owned by miners Potash Corp of Saskatchewan (>> Potash Corporation of Saskatchewan Inc), Mosaic Co (>> Mosaic Co) and Agrium Inc (>> Agrium Inc.), could instead expand facilities at Vancouver, British Columbia or Portland, Oregon, he said. Canpotex accounts for about 20 percent of global sales of potash, used to fertilize corn and other crops.

The move to expand comes as potash prices decline amid weaker currencies in key markets Brazil and India. Germany's K+S AG (>> K&S AG) is building Western Canada's first new potash mine in four decades, along with a port handling facility at Port Moody, British Columbia.

The Prince Rupert project has been in development for a few years, but Seitz said Canpotex will close in on a decision in the next six months. It may be ready to announce it around late 2016, he said.

The Prince Rupert port is served by Canadian National Railway Co (>> Canadian National Railway Company).

Seitz, a former executive with uranium miner Cameco Corp (>> Cameco Corporation), took the Canpotex job on Nov. 1, replacing Steve Dechka.

Canpotex handles offshore sales of potash that the three companies mine in the Canadian province of Saskatchewan.

Separate contract negotiations between potash suppliers Canpotex, Belaruskali and Uralkaliy PAO (>> Uralkaliy PAO) and Chinese buyers including Sinofert Holdings Ltd (>> Sinofert Holdings Limited) are expected to begin soon, setting a new global price floor.

Seitz declined to comment on those talks, other than to say that "all negotiations with the Chinese are tough."

Even so, Seitz said his career in commodities has underlined that all price cycles change eventually.

"In the heat of the moment, there is probably some tendency to run screaming for the door. But if you take a long-term view ... you can remain calm and find opportunities even in those price cycles."

($1 = 1.3348 Canadian dollars)

(Reporting by Rod Nickel in Winnipeg, Manitoba; Editing by Marguerita Choy and Andrew Hay)

By Rod Nickel