Vinson & Elkins (V&E) is mulling plans to re-open its Singapore office, signaling its commitment to Asia Pacific despite having closed its Shanghai base in 2013 and Singapore in 2004.

The US energy firm, which currently has three offices in Hong Kong, Beijing and Tokyo, is in the process of applying to the Singapore Ministry of Law for a Foreign Practice Licence, but is yet to hold a partner vote on the launch.

"The reality is we are still very much in the evaluation stage," said David Liang, the managing partner of Hong Kong, who is heading up the firm's analysis and who sources say could relocate to the city-state in due course.

"Singapore is an energy hub for Asia, so it makes sense for us to be looking at it."

He declined to comment on how big the office might be, but said it is likely the firm would start small and build up. It is understood that V&E has been looking at hiring.

Vinson & Elkins was among the second wave of US firms to enter Asia, launching Singapore first in 1995 led by energy partner Stephen Davis, followed by Beijing in 1997.

A shift in Asia focus meant the firm decided to close Singapore in 2004 but open in Tokyo, following with launches in Hong Kong and Shanghai two years later.

In the summer of 2013 V&E said it was pulling the plug on its Shanghai base, given that most of its clients – Chinese state owned energy businesses – were located in the Chinese capital.

Two of its senior partners then moved to rival firms: M&A partner Tju Liang joining Sidley Austin in Singapore and former Shanghai head David Blumenthal – a corporate oil and gas lawyer – moving to Latham & Watkins in Hong Kong.

As a hub for global companies doing in business in South East Asia, located between India and Indonesia, Singapore is now of key interest to international law firms.

However, with strong local outfits and more than 100 foreign firms operating in the country, nine with local licences, it is fast becoming among Asia's most competitive legal markets.