Sinopec Group, parent of top Asian refiner Sinopec, will complete restructuring of its engineering business by about mid-year before listing the new vehicle via a public stock offering, industry sources said on Monday.

The restructuring would involve the design, construction and services units of Sinopec Group's engineering businesses, the sources said.

"It may take another half year to complete the complicated restructuring and set up a new company," said a source with knowledge of the plan. "It's too early to talk about an initial public offering now."

Another source said the state energy group aimed to float the new engineering vehicle, but declined give a timetable.

"Sinopec aims to list the new company after it is set up, but it also depends on the performance of the new company."

Sinopec's design and engineering institutes and its construction outfits have a combined workforce of almost 50,000 and annual turnover of about 200 billion yuan ($31 billion), industry officials have said.

Among the units are Sinopec Engineering Inc and Sinopec Luoyang Institute -- both flagship design institutions that specialise in refining and petrochemical projects - and engineering and construction arms in Nanjing and Ningbo.

The listing plan was originally proposed by Sinopec's new chief, Fu Chengyu. Formerly head of China's offshore oil and gas company CNOOC, Fu took the helm at Sinopec Group last April.