Argentine sovereign bond yield spreads over U.S. Treasuries widened six basis points, the widest in a month at 412 basis points.
Argentina's 2038 dollar bond fell 1.5 cents while the 2046 bond issue fell 2.6 cents.
The 2032 par bond was down by 1.5 percent.
Though the bond appeared to be well oversubscribed, some investors questioned the wisdom of investing for a such a long term in a country as volatile as Argentina.
"It's awfully premature for Argentina to issue 100-year bonds," said Jorge Piedrahita, chief executive officer of Puma Investments. "When you look back in history, I'm not sure we can find a 20-year period where Argentina has not defaulted."
Citigroup Inc and HSBC acted as lead book runners on the deal, while Nomura Securities and Banco Santander were co-managers.
Such long-term bonds are unusual, particularly in emerging markets. Mexico issued a 100-year bond in 2010.
Since taking office in late 2015, President Mauricio Macri has implemented several market-friendly reforms to deliver on his promise of normalizing Argentina's economy after years of heavy state intervention and non-payment of international debt obligations under the previous government.
He ended a decade-long dispute with creditors that allowed it to re-enter global credit markets, but Argentina lacks an investment grade rating. S&P and Fitch rate the sovereign a B with a stable outlook, while Moody's has the debt at B3.