Federal regulators have charged two Spanish investors with trading on secret information about BHP Billiton PLC's bid to acquire Potash Corp.

The Securities and Exchange Commission said Tuesday that Juan Jose Fernandez Garcia and Luis Martin Caro Sanchez made illegal profits totaling $1.1 million by betting that Potash's stock price would rise. Garcia was the head of research at Banco Santander SA, which is advising BHP on the deal.

BHP offered last week to pay $130 per share for Potash stock in a hostile attempt to take over the company. The total value of the bid was $38.5 billion.

BHP is the world's largest mining company. Potash is the world's largest producer of fertilizer minerals.

Garcia and Sanchez spent $61,000 earlier this month on contracts that allowed them to buy Potash stock at a set price, the SEC said. The contracts were about to expire. They would have been worthless unless Potash shares gained value quickly.

When BHP announced the bid, Potash shares surged. The traders tried unsuccessfully to move their returns to Spain. Both are residents of Madrid.

The SEC brought the charges in federal district court in Illinois. The investments were traded on the Chicago Board Options Exchange.