WASHINGTON—The Senate Labor, Health, Education and Pensions Committee on Wednesday will hold a hearing on Joshua Gotbaum, an operating partner at New York-based private equity fund Blue Wolf Capital Management L.L.C., whom President Barack Obama nominated in November to be the director of the Pension Benefit Guaranty Corp.

Mr. Gotbaum's hearing comes at a difficult financial time for the PBGC. In fiscal 2009, the agency's deficit nearly doubled to $22 billion from $11.2 billion as the PBGC was hit by huge losses from failed plans it took over.

And more big losses could be on the way. The PBGC in November reported that its potential exposure to future losses from financially weak companies was about $168 billion, up from $47 billion the prior year.

In fiscal 2009, the agency took over 144 pension plans, up from 67 in 2008.