The company foresees investment of more than $40 billion in the Central Asian nation's railway network by 2020.

The paper, maturing on July 10, 2042, was priced to pay an annual coupon of 5.55 percent, below the original yield guidance of 5.70 percent.

It supplements an $800 million issue launched in July.

Order books for the dollar-denominated paper, opened for investors on Thursday, were heavily oversubscribed, with bids from over 100 investors totalling around $2 billion, KTZ said. US investors accounted for 40 percent of the bidders.

"The issue drew significant interest from institutional investors, and the bond was placed along the lower threshold of the reduced price range," the company said.

KTZ's $800 million eurobond was massively oversubscribed, with bids worth a total of $5.2 billion, when launched on the London and Kazakhstan stock exchanges in July, the company said at the time. It bore an annual coupon of 6.95 percent.

Last year, KTZ made a net profit of 123.2 billion tenge ($830 million).