Shares of AK Steel Corp. fell to a new 52-week low Monday after equity downgrades late last week and Monday.

The Middletown steelmaker’s shares closed at $4.99, down 81 cents, or 13.97 percent, from the close Friday . AK Steel shares rose a bit in after-hours trading

The day’s performance came after a downgrade Friday by Goldman Sachs Group Inc. and another Monday by equity research firm Delman Rose.

Goldman Sachs downgraded AK’s shares from “neutral” to “sell” last week. Delman Rose downgraded the stock from “buy to “hold.”

Goldman Sachs cited “continuing weak flat steel prices, a highly leveraged balance sheet, high pension funding requirements, high (capital expenses) to fund its raw material strategy, and no sign of a turnaround in its lucrative electrical steel end market.”

In April, AK reported a net loss of $11.8 million, or 11 cents per diluted share of common stock, for the first quarter of 2012, compared to net income of $8.7 million, or 8 cents per diluted share, for the first quarter of 2011 and a net loss of $193.9 million, or $1.76 per share, for the fourth quarter of 2011.

The stock’s current 52-week range before Monday’s closing was $5.51 to $16.75.

An AK spokesman could not be reached for comment.

Based in Butler County’s West Chester Twp., AK has a Middletown steel plant.