WASHINGTON, Jan 5 (Reuters) - Leading auto supplier Visteon Corp VC.N and U.S. pension insurers reached a $55 million agreement to strengthen retirement accounts covering 5,300 former employees, officials said on Monday.

The Pension Benefit Guaranty Corp (PBGC) said Visteon will accelerate a $10.5 million cash contribution, provide a $15 million letter of credit, and work with certain affiliates to ensure up to $30 million in contingent obligations.

Federal pension insurers can take steps to ensure the health of plans when more than 20 percent of employees lose their jobs in a plant closing. As part of its ongoing restructuring, Visteon halted operations at two Indiana plants in 2007 and 2008. (Reporting by John Crawley; editing by Richard Chang)