Johnson Controls (JCI) said there was "no reason" not to still be attracted by A123 Systems although the company is currently being evaluated for a potential purchase by Chinese operation Wanxiang.

The Chinese require approval from the Committee on Foreign Investment in the United States (CFIUS) with JCI waiting in the wings should regulatory permission not be forthcoming.

"There is no reason not to be interested," JCI power solutions [batteries] president Alex Molinaroli told just-auto at the North American International Auto Show (NAIAS) in Detroit.

"We were interested in the first place and we remain interested. CFIUS has a process that we really can't affect and it is a process [in which] they do all their own research with the cabinet departments.

"It is kind of hard to know what is going to happen. It has got to be available and it is not available. For us it was really not about China - it was more around some of the technologies. At the right cost it made a lot of sense - it was going up in US$5m increments."

A123 chose Wanxiang's offer of US$257m against a set of complementary bids from JCI for the automotive and government assets and NEC for the grid and commercial assets.

Molinaroli also took the opportunity to rebuff speculation JCI would have reduced the workforce had it won the tender for A123.

CFIUS is an inter-agency committee authorised to review transactions that could result in control of a US business by a foreign person in order to determine the effect of such transactions on what it describes as "national security".