TOKYO, June 3 (Reuters) - A safety test scandal at

Japanese automakers widened on Monday, with Toyota Motor ( TM )

and Mazda ( MZDAF ) both halting shipments of some

vehicles after Japan's transport ministry found irregularities

in applications to certify certain models.

The irregularities were also found in applications from

Honda ( HMC ), Suzuki and Yamaha Motor ( YAMHF ), the

ministry said. The automakers were found to have submitted

incorrect or manipulated safety test data when they applied for

certification of the vehicles.

The ministry ordered Toyota ( TM ), Mazda ( MZDAF ) and Yamaha to suspend

shipments of some vehicles. It said it will conduct an on-site

inspection at Toyota's ( TM ) central Aichi prefecture headquarters on

Tuesday.

The latest revelations came after the ministry requested

automakers in late January to investigate certification

applications following a safety test scandal at Toyota's ( TM )

Daihatsu compact car unit that emerged last year.

Monday's developments are also likely to heighten focus on

Toyota's ( TM ) annual general meeting later this month. Influential

proxy advisory firms Institutional Shareholder Services and

Glass Lewis have recommended shareholders vote against

re-electing Akio Toyoda as chairman at the meeting.

In a report to shareholders, ISS singled out the "spate of

certification irregularities" at the Toyota Group.

"As the person in charge of the Toyota Group, I would like

to sincerely apologise to our customers, to car fans, and all

stakeholders for this," Toyoda, the grandson of the automaker's

founder and its former chief executive, told a press conference.

He said the cars did not go through the correct

certification process before being sold. The world's biggest

automaker by volume said it temporarily halted shipments and

sales of three car models made in Japan.

The scandals at the automakers are proving to be a sore

point for the government, which has otherwise earned praise from

investors and executives for its corporate reforms. Yoshimasa

Hayashi, Japan's top government spokesperson, called the

misconduct "regrettable".

SHARES FALL

Toyota ( TM ) said its wrongdoing occurred during six different

tests conducted in 2014, 2015, and 2020. Affected vehicles were

three production models - the Corolla Fielder, Corolla Axio and

Yaris Cross - and discontinued versions of four popular models,

including one sold under the Lexus luxury brand.

In one example, it had measured collision damage on one side

of a model's bonnet while it was required to do so on both

sides.

In other instances, it said it conducted certain tests

through development testing under more strict conditions than

those set out by the ministry that did not meet the government's

requirements.

Toyota ( TM ) said it is still investigating issues related to

vehicle fuel efficiency and emissions, and aimed to complete

that inquiry by the end of June.

It added there were no performance issues that violated

regulations and customers did not need to stop using their cars.

Toyota ( TM ) shares closed down 1.8%, underperforming a 0.9% gain

in the broad Topix index.

Mazda ( MZDAF ) suspended shipments of its Roadster RF sports car and

the Mazda2 hatchback from Thursday last week after finding

workers had modified engine control software test results, it

said in a statement.

It also found crash tests of the Atenza and Axela models,

which are no longer in production, had been tampered with by

using a timer to set off airbags during some frontal collision

tests, instead of relying on an on-board sensor to detect a hit.

Mazda ( MZDAF ) shares fell 3.3%.

Yamaha said it had halted shipments of a sports motorcycle.

Honda ( HMC ) said it had found wrongdoing in noise and output tests

over a period of more than eight years to October 2017 on some

two dozen models that are no longer being produced.

(Reporting by Daniel Leussink and Rocky Swift; Additional

reporting by Kaori Kaneko and Satoshi Sugiyama; Editing by

Edwina Gibbs, David Dolan and Muralikumar Anantharaman)