After media reports suggested that China had reached an agreement to buy more than 100 Russian fighter jet engines, Russian plane engine manufacturer SALUT told the Global Times on Wednesday that Beijing had not ratified the deal.

"The contract will involve 140 to 150 engines, but it has not been confirmed by authorities in Beijing," Alexander A. Drozhzhin, the head of press for SALUT, told the Global Times at the Aviation Expo in Beijing on Wednesday.

The Russian state arms exporter, Rosoboronexport (ROE), announced in July a sale of 123 SALUT-made AL-31FN turbofan engines to China for $500 million, the Washington Times reported late August.

The engine is a variant of that used in the Su-27 and Su-30MKK/MK2 fighter jets and is designed to be used on China's single-engine J-10 aircraft, the paper added.

According to Drozhzhin, the reported deal involves the third series of the AL-31FN, which have a maximum thrust of 12,500 kilograms and 2,000-hour service life.

The AL-31FNs currently used on China's J-10s have 11,700-kilogram thrust and 1,500-hour service life, Drozhzhin told the Global Times.

China's air force development made headlines earlier this year after news about the prototype J-20 stealth plane emerged. However, aircraft engine design and manufacture have been lagging behind.

Since 2009, home-made Taihang engines, developed and produced by the Aviation Industry Corporation of China (AVIC), have been fitted to the double engine J-11 fighter jets, its J-15 carrier-based variant and an upgraded version of the J-10 single engine fighter.

Lin Zuoming, president of AVIC, told the Global Times in a previous interview that it had taken 20 years to develop the Taihang, and that  work on the engine was progressing very well.

When asked if Chinese engines such as the Taihang would have any impact on the export of Russian engines, Drozhzhin said that SALUT was confident in the future sale prospects of their product.

"The Taihang's appearance on the J-15 meant its reliability and performance had met with high demands, such as those for carrier-based aircraft. That was a significant boost for China's flight engine development," Daniel Tong, Chinese aviation observer and founder of the website Chinese Military Aviation, told the Global Times.