The federal Pension Protection Act of 2006 seems to have slowed large U.S. employers’ exodus from the defined benefit pension system.

Consultants at Watson Wyatt Worldwide, Washington, have come to that conclusion in a report based on a survey of large “Fortune 100″ companies.

The consultants found that 54 of the biggest employers still offer defined benefit plans to new employees.

The percentage of Fortune 100 companies offering defined benefit plans has dropped just 4 percentage points, from 58%, since 2007.

Between 2003 and 2006, the percentage of employers offering defined benefit plans plunged 25 percentage points, from 83%, the Watson Wyatt consultants report.

PPA provisions seem to have encouraged employers to keep their defined benefit plans by creating a more supportive environment for the plans, the consultants write.