British companies involved in the world's largest trial of a four-day working week have mostly decided to retain it in what campaigners hailed as a breakthrough for a better work-life balance.

That may still be far from the leisurely 15-hour working week British economist John Maynard Keynes in 1930 predicted could be the fruit of mass automation - and surveys show the vast majority of firms have no plans for going the same route.

Yet the past two years have seen many such experiments as the COVID-19 pandemic, rising energy bills and labour shortages have prompted employers to re-examine the work week for reasons ranging from employee well-being to cost-savings.

Whether they will have the longevity of France's landmark 35-hour working week bill, enshrined into law in 2000, remains to be seen. And they stand in contrast to the gruelling hours and precarious working conditions which remain the lot of many millions of workers around the world.

The following are examples of some of the schemes:

BRITAIN - Employees at 61 companies worked an average of 34 hours across four days between June-December 2022, while earning their existing salary. Of those, 56 companies, or 92%, opted to continue like that, 18 of them permanently. A number of participants said job retention and recruitment had improved during the trial.

SPAIN - The left-wing government launched a pilot project in December to help small and medium-sized industrial companies cut the working week by at least half a day without denting salaries in an attempt to boost productivity. The country's telecom giant Telefonica separately offered its employees a four-day week - but in exchange for a 12% pay cut.

ITALY - Italy's biggest bank Intesa Sanpaolo last year offered staff the option of a four-day working week on the same salary from this January, the first such move by a major Italian employer. Intesa said it was looking at shortening the working week to curb its rising electricity bills.

PAKISTAN - Saving on fuel bills was also a major motivation for authorities in Pakistan who last June included provisions for shorter working hours in a wide-ranging energy conservation plan. In its case, the cut was to five days from six.

GERMANY - A pay deal agreed last April for tens of thousands of workers at Germany's public-sector banks also included a one-hour reduction to a 38-hour working week from 2024. Germany has been a forerunner in adapting working weeks, either as part of wage-bargaining or to avoid redundancies in economic slowdowns.

Bosses at car giant Volkswagen said back in the 1990s that a four-day week was hurting competitiveness and pushed for it to be increased. More recently it and other auto-makers have been implementing a 35-hour working week.

CHILE - Santiago-based career services firm People&Partners was among the early adopters of a four-day week during the COVID-19 pandemic. It said it was inspired to make the move after Chile's mass protests in 2019, followed by economic hardships from the pandemic, took a toll on its employees.

NORDICS - Some public administrations in Denmark and Iceland have already adopted 4-day weeks. Travel company Nordic Visitor, with offices in Iceland, Scotland and Sweden, reduced the working week to 35 hours from 40. It reported a rise in employee satisfaction, fewer sick days and bigger profits.

NEW ZEALAND - Estate planning company Perpetual Guardian experimented with a four-day week in 2018 and subsequently made it permanent, citing rising productivity and lower absenteeism. Consumer goods giant Unilever has also experimented with a four-day working week for local staff.

(Compiled by Mark John; Editing by Christina Fincher)