Mitsui & Co. and subsidiary Mitsui Knowledge Industry Co. have separately taken a 4.23 percent stake in U.S. biotechnology venture Gene Networks Inc. for $250,000 each, the parent firm said Monday.

The major trading house said the investment is in line with its business strategy of branching out to biotechnology businesses by investing in startup firms.

Based in Wilmington, Del., GNI specializes in measuring the expression levels of genes in a living cell or tissue, hoping to aid in the development of new drugs.