UPDATE 1-AK Steel posts loss after big tax charge

July 24 (Reuters) - AK Steel Holding Corp posted a steep second-quarter loss on Tuesday as the company took a charge for its U.S. taxes.

The net loss was $724.2 million, or $6.55 per share, compared with a year-earlier profit of $33.1 million, or 30 cents per share.

Excluding a one-time noncash charge of $736.0 million for a valuation allowance on deferred tax assets, earnings per share were 10 cents.

Analysts on average had forecast earnings of 6 cents per share, according to Thomson Reuters I/B/E/S.

Net sales for the quarter were $1.54 billion, down 14 percent, as both shipments and selling prices weakened.

The company said it had not issued a profit forecast because of the economic uncertainty, but that it expected to do so later in the quarter.

Shares of AK Steel, which at Monday's close were down nearly 40 percent so far this year, rose 1.6 percent in premarket trading to $5.08.