China, the top potash importer, acquired a 12.5% stake in Uralkali, the biggest producer of the fertilizer, in a deal which some investors believe will cut the chances of a revival in prices of the nutrient.
China Investment Corporation - China's sovereign wealth fund, with some $575bn under management as of last month - became the second largest shareholder in Russia-based Uralkali through swapping Uralkali debt into shares worth $2bn.
The announcement comes 10 months after CIC bought the bonds, which came with the option to convert into shares, from Suleiman Kerimov, Uralkali's biggest shareholder, and three of his partners.
Mr Kerimov will remain the top shareholder, with a stake of 22%, with his business partners Filaret Galtchev and Anatoly Skurov owning 7% and 4.8% respectively.
And it comes at a critical period for Uralkali, and for the potash market, which the group threw into turmoil at the end of July by disbanding the Belarusian Potash Company cartel, with Belaruskali, which was responsible for more than 40% of world trade.
The break-up of such a powerful marketing consortium has provoked a tumble in potash prices, although not yet the plunge of potentially more than 25% in values, to below $300 a tonne, that Uralkali said at the time could be on the cards.
It has caused a political rumpus, angering the Belarusian government, which owns Belaruskali and depends on potash for a large chunk of state revenues, and which orchestrated a month ago the arrest of Victor Baumgertner , the Uralkali chief executive, on grounds of abusing his position as BPC chairman.
Uralkali's is further surrounded by uncertainty over reports that Mr Kerimov is in talks to sell his stake, with Vladimir Kogan, a financier and former state official once dubbed "Putin's banker", viewed as one potential buyer.
A deal is viewed as one ingredient of a cocktail which would lead to a resolution between Belaruskali and Uralkali, which could potentially lead to the reformation of the BPC cartel and a renewal of price discipline which would put upward pressure on values.
National vs investment interests
Indeed, CIC may have opted to become a shareholder now to increase its influence over Uralkali, and on the potential for a BPC rebirth, some investors believe.
"For BPC to reform probably makes sense for Uralkali shareholders, as long as it does maintain price discipline, because it will be able to sell potash for more and make more profit," a fund manager, and former Uralkali shareholder, told Agrimoney.com.
"But for China as a whole, it would be far better if BPC remained for ever off the map. China wants cheap potash, which it looks like getting now the cartel has been broken up."
China, which has few potash reserves of its own, has considered other measures of working its influence on the production of a nutrient which was, until the BPC break-up, tightly controlled, with more than 70% of trade controlled by BPC and its North American peer Canpotex.
Several state-owned Chinese companies, including Sinochem, three years ago mulled a bid for Canada's PotashCorp, to rival a $39bn hostile offer from BHP Billiton, which foundered after failing to receive backing from Canadian officials.