Post-earthquake/tsunami effects on automakers and OEM suppliers continued in Japan on Tuesday with Toyota and Honda extending their production suspensions until at least Sunday, and Mitsubishi uncertain beyond 25 March while OEM infotainment supplier Sony, which has five suspended or output-restricted factories, reportedly is considering shifting some production overseas.

Toyota further delayed restarting its Japanese assembly lines and Sony cut output at five more plants and as the country’s catastrophic earthquake plays havoc with the global supply of parts and products, Reuters reported, noting that global electronics and automakers have been hardest hit by the turmoil.

In an illustration of how the ripples are spreading, global miner Rio Tinto warned the disruptions posed a threat to its expansion plans, the report added.

Power cuts, crippled infrastructure and a shortage of parts are hampering maufacturers’ efforts to restart production and such is Japan’s position in the global supply chain that companies from Apple to General Motors and Nokia are feeling the impact, the news agency said.

Toyota said in a brief statement suspended vehicle production at its 12 TMC and subsidiary vehicle manufacturing plants would will continue until (and including) 26 March, a scheduled Saturday production day.

The automaker added it had, however resumed production of replacement parts on 17 March and resumed the production of parts for overseas production (including knockdown assembly kit parts) on 21 March.

The Japanese automaker had originally intended to begin production again today (22 March) following the country’s massive earthquake, but the new setback will see total unit losses widen from 95,000 to 140,000 units.

Citing “component supply” issues, Toyota remains coy about releasing specific company details, but noted the shortages are electronic, rubber and resin parts as well as some plastic types of.

A spokesman for the automaker said it was important to put the loss of 140,000 units in the context of a planned 8m-plus units build schedule this year.

Toyota has also addressed the issue of how to pay its considerable workforce, who have now been off since 14 March.

“Last week, from 14-18 March, the workers had non-operation day[s],” the spokesman in Tokyo told just-auto.

“The workers are not paid but they will not lose that income because work not done on a non-operation day is scheduled to be made up another day, for example a Saturday. From 21 March, the days are regular work days so they get paid.”

Mitsubishi Motors said in a statement it had operated both day and night shifts on Tuesday 22 March and production would now be suspended on Wednesday 23 March.

On Thursday 24 March, MMC plans to operate only the first shift at its PMC plant while production at Okazaki and Mizushima remain suspended.

“As for [Friday 25 March] and thereafter, operations will be carefully deliberated according to the surrounding circumstances,” the automaker said.

Sony told Reuters five more of its plants, mostly in central and southern Japan, were hit by parts shortages stemming from the disaster and would close or reduce output until the end of the month.

“If the shortage of parts and materials supplied to these plants continues, we will consider necessary measures, including a temporary shift of production overseas,” Sony said in a Tuesday statement.

The plants make products such as digital and video cameras, televisions and microphones, Sony said.

A sixth plant in Chiba, north of Tokyo, was set to resume production on Tuesday, but it could be interrupted by rolling blackouts that are affecting some areas supplied by Tokyo Electric Power (TEPCO) , the operator of the stricken Fukushima nuclear plant.

Including two factories only partially restarted last week, 15 of Sony’s 25 Japanese plants are currently affected. It has 54 plants worldwide, Reuters added.

The report noted that Japan’s grip on the global electronics supply chain is causing particular concern – the country produces around a fifth of the world’s computer chips and exported JPY7.2 trillion (US$91.3bn) worth of electronic parts last year, according to Mirae Asset Securities.

“There are a huge number of little bits of the high-tech food chain which are done nowhere but in Japan,” Sam Perry, senior investment manager of Pictet Japanese Equity Selection Fund, told the news agency. “Nobody else has the quality or the consistency, and in some cases the technology, to do it.”

Japan dominates with the supply of LCD film and sealants for semiconductors, among other areas, Perry added. “You simply can’t do high-tech without Japan.”

Fujifilm Holdings , the largest producer of triacetyl cellulose film used in making LCD panels, said its main factories are all west of Tokyo and were not directly affected. It has other facilities in northeast Japan, but said any disruptions were unlikely to damage its earnings.

Konica Minolta, the second-largest maker of the LCD film, said its three factories in the Tokyo region had been affected by the rolling power cuts. Company officials declined to specify to Reuters what these factories produce.

Renesas Electronics Corp , the world’s No.5 chipmaker, restarted operations on Saturday at a semiconductor plant in Yamagata prefecture, in northwest Japan, a company spokeswoman told Reuters on Tuesday – leaving output suspended at six of the firm’s 22 factories in Japan.

Rio Tinto, the world’s No.2 iron ore miner behind Brazil’s Vale , is worried the disaster will disrupt supplies of mining equipment, tyres and parts, which could set back some of its expansion plans.

“The impact of the Japanese earthquake and tsunami have been many and diverse, and they affect us,” Rio’s head of iron ore Sam Walsh told an industry conference in Perth.

“Some steel mills have suspended operations and suppliers of heavy equipment, such as Hitachi, have been impacted,” he said.

Honda said in a Tuesday statement it would extend the suspension of production of finished vehicle units until 27 March at uts Sayama Plant at Saitama Factory and Suzuka Factory (Suzuka, Mie) autombile factories and Kumamoto (Ozu-machi, Kikuchi-gun, Kumamoto) motorcycle plant. It had previously suspended production until Wednesday 23 March after ” onsidering the current situation of the nationwide recovery efforts in Japan and the supply of parts from our suppliers”.

“Concerning operations from 28 March on, Honda will make decisions based on the status of the recovery of Japanese society as a whole as well as the supply of parts. We deeply regret any inconvenience this may cause our customers, and request their understanding during these challenging times,” the statement added.

A fifth of Honda’s leading Japan-based suppliers affected by the earthquake have said it will take “more than a week” to recover, Honda earlier told Reuters.

On the other hand, in a sign of some return to normality, Japan’s top three steelmakers reported some progress in restoring production.

Nippon Steel told Reuters output at the three blast furnaces at its main plant in eastern Japan had recovered to pre-quake levels, while JFE Steel said two blast furnaces at its 10m tonnes a year plant near Tokyo were now operating normally.

Additional reporting: Graeme Roberts and Simon Warburton