The chairman of the ICC, David Morgan, revealed the governing body were seriously considering the innovations as they look to increase the appeal of cricket's longest format.

At an ICC meeting at Lord's last week it was resolved to begin trials with the aim of playing a day-night Test as early as next year.

And while Morgan does not believe four-day cricket could happen in that time frame, he believes dwindling Test crowds in some countries mean the ICC must act to keep it at "the pinnacle of the sport".

"There will not be four-day Test match cricket in one year's time although we may have day-night Test cricket," he told BBC World Service.

"Four-day Test match cricket is just one of many options that we are contemplating to make it the pinnacle of the sport which it has been for over a hundred years.

"Four-day Tests are just an option and more probable is the introduction of day-night Test cricket.

"Some Test matches finish in four days and some in five and we want as many people as possible to turn up to these matches. We want Test matches in certain countries to be more spectator-friendly.

"It is the customer and not just the player we have in mind on our quest to enrich Test match cricket which is the most demanding form of our great sport."

Last month's World Twenty20 was played to packed stadiums around England as the popularity in that form of that game continues to grow.

By contrast Test cricket in countries such as South Africa and West Indies is struggling to pull in the crowds, with the status of the game suffering a further blow in May when Windies captain Chris Gayle admitted his growing disinterest in five-day cricket.

Morgan said the views of players would also be taken into account.

The demands of an already jam-packed calendar have caused some players to voice concern they are being asked to play too much cricket, and Morgan intimated four-day cricket could help alleviate those worries.

"We would only move from five-day to four-day if we considered it to be in the interests of Test match cricket," he added.

"Representatives from the 10 Test playing nations are working and have been for over six months."

Former Australia wicketkeeper-batsman Adam Gilchrist last week urged the ICC not to "tamper" with Test cricket during his speech at the Cowdrey Lecture at Lord's.

Gilchrist, a strong advocate for the traditions of the game, said such innovations should be given trails only in the shorter formats.

"Test cricket should be tampered with as little as is possible. Its rules, customs and playing conditions - like Major League Baseball - should remain as close to how it has been played for the past 130 years," he said.

"Many of cricket's innovations should be applied only in the shorter forms of the game.

"This not only includes the expanded umpire referral system, but especially the mooted introduction of night Test cricket and a different coloured ball needed to accommodate this."