...+ Brazil-based steelmaker Gerdau has been able to gradually reduce debt despite still weak volume demand in Brazil and lower margins in the U.S., the company's two larger operations. + We're affirming our '###-' global scale and 'brAAA' national scale ratings on the company, with a negative outlook. + The negative outlook reflects that although we see credit metrics improving thanks to Gerdau's efficient working capital management and strong free cash generation, there is a one-in-three likelihood of a downgrade if the company is unable to bring its debt to EBITDA to consistently below 4x and funds from operations (FFO) to debt above 20% in the next few quarters. In addition, Brazil's sovereign rating is a cap on Gerdau's due to its exposure to that country, so a negative rating action on the sovereign could also prompt a downgrade of Gerdau. SAO PAULO (S&P Global Ratings) March 20, 2017--S&P Global Ratings affirmed its '###-' global scale ratings on Gerdau S.A. (Gerdau) and Gerdau Ameristeel...