Treasury is looking to raise 1.1 billion rand ($154.5 million) from 2036 bonds and 1 billion rand from 2041 paper, both on the long end of the bond curve.

In Tuesday's early trade, yields were down three basis points to 6.31 percent on the 2015 note while the 2026 yield fell four basis points to 7.79 percent, compared to their closes on the Johannesburg Stock Exchange where trades are reported.

The bourse looked to come under pressure after falling more than two percent on Monday, with the JSE's September futures contract down 0.35 percent ahead of trade opening at 0700 GMT.