The chief executive of Nissan Motor and Renault, Carlos Ghosn, said on Tuesday the two automakers’ partnership was sufficient to cover a range of powertrain technologies and there was no need to seek tie-ups with others in that area.

“We are maximising our Alliance,” he told Reuters, noting that Nissan, for instance, was spearheading development of hybrid technology while its French partner was taking the lead in diesel engines.

Ghosn was speaking to the news agency at the opening of the Nissan Advanced Technology Center, a 90bn yen ($US750m) facility in Kanagawa Prefecture, south of Tokyo, where Nissan will develop next-generation safety and environmental technologies.

Reuters noted that Japan’s third-biggest automaker trails domestic rivals Toyota and Honda in clean vehicle technology, but Ghosn has said Nissan had the means to catch up by saving R&D costs and time together with Renault. The partners share several vehicle platforms and engine technology as well as manufacturing sites.

Asked about tying up with a US automaker a day after DaimlerChrysler announced the sale of its US Chrysler arm to a private equity firm, Ghosn told the news agency the time was not right, repeating his view that Nissan and Renault needed to improve their businesses before considering such a move.

“There’s no change in our stance,” he was reported to have said. “We’re not talking to anybody. Front stage or back stage, there’s nothing going on.”

He added that any expansion of the Nissan-Renault partnership would be aimed at realising further opportunities rather than out of necessity.

Reuters added that Ghosn had expressed interest last year in forming a three-way alliance with a US-based automaker to cement a global partnership that now spans Japan and Europe, but has said there was no urgency after talks with General Motors failed to produce a partnership last autumn.