Jana Partners LLC, the $10 billion hedge-fund firm run by Barry Rosenstein, bought shares of FMC Corp. and exited stakes in Sirius XM Holdings Inc. and Juniper Networks Inc. during the second quarter.

Jana bought 4.99 million shares of chemicals maker FMC valued at $355.5 million as of June 30, according to a filing with the U.S. Securities and Exchange Commission today. It was the second-largest new holding after oil and and natural gas company Apache Corp., which has been previously disclosed. The New York-based firm also took a position in Equity Commonwealth that was valued at $144 million and added substantially to its stake in Hertz Global Holdings Inc.

Charles Penner, a partner at Jana, declined to comment on the filing.

Jana, which is known for taking stakes in companies and then urging management to make changes to boost the stock price, is listed as the sixth-largest holder of Philadelphia-based FMC with a 3.75 percent stake. Dan Loeb’s Third Point LLC also today disclosed a new position in FMC, adding 1.55 million shares valued at $110 million as of June 30.

FMC shares declined about 7 percent in the second quarter when it cut its 2014 profit forecast and blamed prolonged winter weather in North America and drought in Brazil for hurting sales of herbicides and insecticides. The shares rose 2.2 percent to $66.09 at 12:35 p.m. in New York trading, trimming its decline this year to 12 percent.

Hertz, AIG Additions

Jana disclosed it increased its Hertz holdings to 5.92 million shares with a market value of $166 million as of June 30, up from 125,000 shares in the prior quarter. It also added to its holdings in Actavis Plc and insurer American International Group Inc. Its biggest holdings listed are Walgreen Co. and Equinix Inc. It sold shares of Sirius valued at $231.3 million as of June 30.

Money managers who oversee more than $100 million in U.S. equities must file a Form 13F within 45 days of the end of each quarter to list their holdings in stocks that trade on U.S. exchanges, as well as options and convertible debt. Hedge funds are lightly regulated pools of capital whose managers can invest in any asset and share in annual profits.

–With assistance from Jack Kaskey in Houston and Beth Jinks in New York.