Apple Inc, Google Inc and two other Silicon Valley companies are making progress toward settling a closely watched lawsuit where tech workers allege the companies conspired to avoid competing for each other's employees in order to drive down wages.

At a hearing on Thursday in federal court in San Jose, California, Google attorney Robert Van Nest said the companies and the plaintiffs have been consulting daily with a mediator to try to resolve the dispute, and that they are making progress.

Kelly Dermody, an attorney for the plaintiffs, agreed with the assessment. Roughly 60,000 tech workers won permission to sue as a class action. Trial is currently scheduled to begin in May.

The case began in 2011 when five software engineers sued Apple, Google, Adobe Systems Inc, Intel Corp and others over an alleged conspiracy to suppress pay by agreeing not to recruit or hire each other's employees.

These defendants were accused of violating the Sherman Act and Clayton Act antitrust laws by conspiring to eliminate competition for labor, depriving workers of job mobility and hundreds of millions of dollars in compensation.

The case has been closely watched by Silicon Valley, with much of it built on emails among top executives, including the late Apple Chief Executive Officer Steve Jobs and former Google Chief Executive Officer Eric Schmidt.

Walt Disney Co's Pixar and Lucasfilm units and Intuit Inc have already agreed to a settlement, with Disney paying about $9 million and Intuit paying $11 million.

The case in U.S. District Court, Northern District of California is In re: High-Tech Employee Antitrust Litigation, U.S. District Court, Northern District of California, No. 11-02509.