BOSTON (AP) — General Electric is being investigated by federal regulators for a $15 billion hit it took to cover miscalculations made by an insurance unit.

The company revealed last week that it would take a $6.2 billion charge in its fourth quarter after a subsidiary, North American Life & Health, underestimated how much it would cost to pay for the care of people who lived longer than projected.

During a conference call Wednesday to discuss its fourth-quarter earnings report, the CEO of GE Transportation said that the company had been notified that the Securities and Exchange Commission is investigating the process that led to the mishap.

GE's Jamie Miller said the investigation is in its early stages and that the company is cooperating fully.