UPDATE - U.S. pension agency's deficit grows to a record Tuesday October 14, 1:23 pm ET By Susan Cornwell WASHINGTON, Oct 14 (Reuters) - The deficit at the U.S. agency that insures pensions grew to a record $8.8 billion at the end of August, the agency's director said on Tuesday, and he warned that U.S. taxpayers might ultimately have to bail out the agency. The Pension Benefit Guaranty Corp., which insures retirement plans for 44 million current workers and retirees, had forecast a $5.7 billion deficit earlier this year. The PBGC's shortfall "is the largest in its history and is...