About 10.1% of the shares of equipment maker Oshkosh Corp. have been purchased by a private investment group, according to industry news reports. The purchase of more than 8.7 million shares by Capital World Investors, a Los Angeles-based division of Capital Research and Management Co., was publicly disclosed via a mandatory filing with the US Securities and Exchange Commission. The purchase follows similar big stakes in the company purchased by BlackRock Inc., of New York, (6.6 million shares) and Fidelity Management & Research Co., of Boston, (5.6 million shares), both in February. In December, investor Carl Ichan and associates dumped their shares in Oshkosh — once as high as 9.51% — after an unsuccessful hostile takeover of the company’s board of directors. Oshkosh is a subsidiary of JLG Industries, a manufacturer of aerial work platforms and telehandlers sold under the JLG, SkyTrak and Lull brands.