The Securities and Exchange Commission has accused unknown Martek Bioscience Corp. investors of insider trading ahead of the company's announcement last week of its $1.09 billion sale to Royal DSM NV, according to recent court filings.

On Dec. 21, Netherlands-based Royal DSM said it would pay $31.50 per share for Columbia, Md.-based Martek, marking a 35 percent premium to its stock value on Dec. 20. Martek makes nutritional supplements for infant formula and Royal DSM makes nutritional supplements, vaccine ingredients and industrial chemicals. The deal is expected to close in the second quarter.

In a complaint filed in federal court in Manhattan on Dec. 22, the SEC said unknown buyers bought 2,615 call option contracts between Dec. 10 and Dec. 15, through a UBS Ltd. account. The options were sold on the same day the buyout deal was publicly announced, putting those buyers in a position to gain $1.2 million in profit.

There was no information made public about the deal prior to the companies' Dec. 21 announcement.

The SEC wants the court to require the buyers to return the profits and pay a fine. On Dec. 23 the court agreed to freeze assets in the UBS account and ordered the buyers to come forward. A hearing date of Jan. 6 was set.