Also

* Alcoa Inc. said first-quarter net income fell 31% to $151 million, or 17 cents a share. Sales rose 4% to $5.11 billion.

* Network Associates Inc. of Santa Clara, Calif., said it would pay $120 million to acquire Entercept Security Technologies of San Jose, whose technology detects network intrusions, marking its second acquisition in a week.

* El Segundo-based Computer Sciences Corp. said it would buy Level 3 Communications Inc.’s Internet hosting unit, gaining access to 100 clients and $40 million in expected sales this year.

* UAL Corp. Chief Executive Glenn Tilton cut his salary by an additional 14% to $712,500, bringing his total pay reduction for this year to 25%. The company also reached six-year agreements with two unions, the Assn. of Flight Attendants and the Professional Airline Flight Control Assn., as part of an effort to reduce costs.

* AOL Time Warner Inc. has hired Shawn Bentley, former attorney for the Senate Judiciary Committee, as a lobbyist in charge of copyright and intellectual property issues. He replaces Elizabeth Frazee, who left to start a consulting business.