Spain's stock market regulator Tuesday suspended trade in the shares of oil major Repsol YPF SA (REP.MC) and its top shareholder, Sacyr-Vallehermoso SA (SYV.MC), amid press speculation that Sacyr may sell part of its Repsol stake.

The regulator didn't give a reason for the suspension, or say when it will be lifted.

Late Monday, state-owned news agency Efe reported that at least 85% of Sacyr's creditors are willing to refinance a EUR4.9 billion loan used by the cash-strapped construction company to buy its Repsol stake.

As part of the refinancing deal, Sacyr is considering selling 8%-10% of Repsol to an industrial partner or even to Repsol itself.

According to recent press reports, other potential buyers are China Petroleum & Chemical Corp. (SNP), or Sinopec, India's Essar Energy (ESSR.LN), Colombia's Ecopetrol (EC), Italy's Eni SpA (E), as well as Arab funds such as Qatar Holding.

-By David Roman, Dow Jones Newswires, +34 91 395 8127; david.roman@dowjones.com