SHANGHAI (REUTERS) - China's top economic planner has approved two subway system projects worth 129.8 billion yuan (S$27.8 billion), according to documents published on Tuesday, continuing a run of infrastructure approvals as the government looks to support its slowing economy.

The National Development and Reform Commission said on its website that it approved the third construction phase of a subway system in Wuhan, capital of central Hubei province, which it estimated to cost 114.9 billion yuan.

It also gave the go-ahead to a revised 14.86 billion yuan plan for a urban rail system in Changchun, capital of northeastern Jilin province. Both schemes were approved earlier this month, the NDRC's statements showed.

In addition, the NDRC approved a feasibility study for a proposed renovation of security facilities at the Beijing Capital International Airport, which is pegged to cost 506 million yuan.

China's economic growth slowed to a six-year low 7 per cent in the first quarter as demand at home and abroad faltered, and recent data showed weakness persisted into the second quarter.

Last week, the State Council said it would step up"effective investment" in key sectors such as rural power infrastructure to support the economy.