Microsoft Chairman Bill Gates' investment vehicle, Cascade Investment LLC, and the Bill & Melinda Gates Foundation continued their recent acquisitions of stocks in the medical industry, according to a regulatory filing Wednesday. In terms of number of shares purchased, the three largest additions to existing stakes in the second quarter were all in pharmaceutical companies. Gates bought another 2,589,000 shares of Eli Lilly & Co., raising his holdings to 2,775,000 shares worth $154.5 million on June 30.

He also acquired an additional 1,339,000 shares of Merck & Co., bringing his stake to 2,698,000 shares valued at $136.6 million, as well as 1,202,000 shares of Pfizer Inc. for holdings of 2,242,000 shares worth $78.5 million. Gates added to his holdings in other medical companies during the second quarter as well, buying 293,000 shares of Abbott Laboratories, 335,000 shares of Bristol-Myers Squibb Co., 328,000 shares of Icos Corp., 600,000 shares of Johnson & Johnson, 256,000 shares of Pharmacia Corp., 274,000 shares of Schering-Plough Corp., and 251,000 shares of Wyeth.