LISBON: Portugal sold all 1.25 billion euros in Treasury bills on offer on Wednesday, but the yield on the longer of two maturities sold rose after recent market turmoil over the exposure of the country's largest listed bank to its troubled founding family's debt.

The IGCP debt agency said the average yield on 12-month bills rose to 0.453 percent from 0.364 percent at a previous auction last month. It sold 850 million euros in this maturity.

The yield on 6-month bills still fell to 0.243 percent from 0.438 percent at the last auction of this maturity in March, which was before Portugal exited its international bailout in May.

Demand outstripped the amount placed by 2.46 times on 6-month bills and 2.05 times on the longer maturity, the IGCP said.