HONG KONG, July 7 (Reuters) - China National Petroleum Corp. (CNPC), the country's largest oil company, has offered to pay between $13.2 billion and $14.5 billion for a 75 percent stake in Spanish oil major Repsol's Argentine unit YPF, the South China Morning Post reported on Tuesday, citing sources.

Executives from CNPC, the parent firm of top Asian oil and gas producer PetroChina, and Repsol have begun talks over the offer and the initial reaction from Repsol's board members has been receptive, the newspaper said.

But Liu Weijiang, a CNPC official in charge of responding to foreign media inquiries, told Reuters that he did not have any information on the deal.

The bid is lower than the $17 billion offer that CNPC was prepared to make, reported by the paper last week.

Repsol had said it received several offers for a stake in YPF. China's top offshore oil and gas producer CNOOC, India's Oil and Natural Gas Corporation and Russian companies are also eyeing stakes in the firm.