LONDON (Reuters) - China sold $6 billion worth of dollar-denominated bonds on Tuesday, double its initial target.

The country’s finance ministry sold the bonds in four tranches. A 3-year issue priced 35 basis points above benchmark U.S. Treasuries, a 5-year bond at 40 bps above treasuries, a 10-year at 50 bps above Treasuries and a 20-year tranche at 70 bps above Treasuries, a source at one of the managing banks said.

The deal comes after a market rally this year that has driven global bond yields sharply lower, significantly decreasing the cost of financing compared with its previous dollar issuance in October 2018.

Order books -- or demand -- for the bonds had been over $20 billion earlier in the day, according to Refinitiv capital markets news service IFR. Thirteen banks had been mandated to lead the issue