Telecommunications giant AT&T will have to deal with a massive charge as a result of new accounting related to its company retirement benefits.

According to the Wall Street Journal, the company has announced a $10 billion loss in the fourth quarter, related directly to long-term pension and post-retirement benefits the company promised over its many years before the wireless revolution – and the low interest rates which have limited pension investment earnings.

The company dropped its pension discount rate by a full percentage point at the end of 2011, resulting in a $12 billion accounting loss. Those losses were offset from a relatively good spree of investment success – the company actually earned 8.25 percent in its most recent profit cycle – though the company is also lowering its projected returns as it expects continued uncertainty in the markets in the year ahead.