China United Network Communications Group Co Ltd, the country's second-largest telecom carrier by subscribers, has teamed up with Alibaba Group Holding Ltd to sell its assets on the latter's online auction platform.

The move makes China Unicom the first central State-owned enterprise to auction assets on an internet platform, as part of the Beijing-based company's broader push to deepen its mixed-ownership reform.

According to China Unicom, 150 of its branches have opened accounts on Taobao, an e-commerce platform of Alibaba, to sell what it calls "dead" assets, to make better use of existing resources and boost efficiency.

Such assets include old network equipment, scrap copper, air conditioners, mobile phones and other products. China Unicom has already disposed of 151 batches of such assets on Taobao, which have boosted returns on assets by 10 to 50 percent, the company said in a statement.

Su Baohe, general manager of the goods purchasing and management department at China Unicom, said the company will also partner with Alibaba to build an open, transparent and efficient asset-trading platform for other large-scale Chinese enterprises.

"We will further leverage this successful experience with Alibaba, by exploring innovative retail consumption scenarios to create a smart asset-trading platform and to promote the use of internet functionality to optimize corporate assets," Su said.

China Unicom is deepening its $11.7 billion mixed-ownership reform, seeking rejuvenation via innovation and brainpower from private-sector internet heavyweights.

Last August, the company announced that Baidu Inc would invest 7 billion yuan ($1.1 billion) in the telecom carrier for a 3.3 percent stake. Earlier this month, Robin Li, CEO of Baidu, shouldered a new role as a board member at China Unicom, as the company revitalizes its corporate structure.

Tencent Holdings Ltd has also invested 11 billion yuan for a 5.18 percent stake, with other investments also coming from Alibaba and JD.

Since then, the Shanghai-listed company has inked a series of deals with Baidu, Tencent and Alibaba in a wide range of areas, such as big data, cloud computing, the internet of things and smart electronic gadgets.

Fu Liang, an independent analyst who has been following the telecom sector for more than 15 years, said China Unicom's move might encourage other SOEs to auction off their assets online, which is also an effective way to rein in corruption.

"The sprawling SOEs have to dispose of tons of abandoned assets every year. This could be a big market," Fu said, adding the move also highlights China Unicom's determination to overhaul almost every aspect of its business.