South Korea's leading city gas provider SK E'&'S Co. has further increased its stake in China Gas Holdings Ltd. as part of ongoing efforts to expand its presence in China's city gas sector, Yonhap News reported on Sunday quoting a source as having said.

The company's stake in the Chinese natural gas service operator has risen to 9.61 percent from 7.8 percent, said the source familiar with the shares that are listed on the Hong Kong Stock Exchange.

SK E'&'S announced earlier this month it would eventually increase its original 5.9 percent-stake in China Gas Holdings by purchasing additional an 5 percent for 120 billion won (US$103 million).

If SK E'&'S continues to purchase as planned, SK Group's total holdings will rise to around 15 percent, solidifying its position as the single largest shareholder of the Chinese energy company. Its affiliate SK Gas is known to also hold 4.49 percent.

SK Group, the third-largest conglomerate in South Korea, now holds 14.1 percent in the Chinese firm through its two units.