Bank of China (BOC), one of the country's five largest state-owned commercial banks, is improving its overseas business layout to support the Belt and Road Initiative.

The bank's vice president Zhang Jinliang said BOC was optimizing distribution and resources in foreign countries, especially in ASEAN, in a bid to help the country push forward the initiative.

The Belt and Road Initiative, proposed by President Xi Jinping in 2013, refers to the Silk Road Economic Belt and the 21st-Century Maritime Silk Road, which aim to enhance international connections via building transportation networks.

Zhang said the reported sale of Nanyang Commercial Bank (NCB), a wholly owned subsidiary of BOC Hong Kong, is the first step in the bank's plan.

According to the NCB's financial report, its total assets stood at 93.6 billion yuan (15.2 billion U.S. dollars) with after-tax profits of 263 million yuan and a non-performing loan ratio of 1.6 percent in 2014.

"The NCB overlaps the BOC in many sectors, which disperses customers and resources," Zhang explained. "Selling the NCB is a strategic decision to simplify management and lower cost."

The sale plan has not been approved by Chinese authorities.

Geng Wei, general manager of BOC's board secretary office, said BOC will continue to offer top-quality services as always and guarantee customer rights, in response to concerns over whether the sale will impact NCB's existing customers.

Meanwhile, the BOC released another notice on Thursday evening, announcing it will recombine and transfer its businesses and assets in ASEAN to the BOC Hong Kong.

As the authorized RMB clearing bank and one of three note-issuing banks in Hong Kong, the recombination will expand on BOC's advantages in customers, products and management, said the notice.

"Transferring businesses and branches in ASEAN is an important measure," Zhang said. "BOC Hong Kong will enhance its competence in ASEAN market to promote China's strategies like RMB internationalization and the Belt and Road Initiative."