China’s higher-quality dollar bonds are suffering their worst sell-off in about seven months as property woes spill into the broader credit market. Spreads on the investment-grade notes — which account for the bulk of offshore dollar securities from Chinese issuers — widened about 8 to 10 basis points Tuesday, traders said. That would be the biggest daily expansion since April after a widening of 7 basis points Monday, according to a Bloomberg index. The selloff has moved well beyond China’s higher-quality property names. Tencent Holdings’ dollar bond spreads widened 12 basis point to 137 basis points Tuesday, set for the…