The phrase "a third greater" is correct and usable in written English.
It can be used when comparing quantities, indicating that one quantity is larger than another by one-third of the original amount.
Example: "The new model is a third greater in capacity than the previous version."
Alternatives: "one-third larger" or "33% more".
The average expenditure per couple is a third greater than the average wage.
The administration's count, 933,687, is almost a third greater; it represents nearly one-sixth of the 6.2 million Medicare recipients in H.M.O.'s.
Mohammad Mustafa, the vice-premier of the Palestinian Authority, told me last month that the gross domestic product per capita in the Palestinian territories was a third greater than Egypt's in 2006; now it is a third less.
In 1995, for example, American adolescents terminated pregnancies at a rate roughly a third greater than their Canadian, English, and Swedish counterparts, around triple that of French teen-agers, and six times that of Dutch and Italian adolescents.
Estimates of leaks from chemical pumps, while small, were twice past estimates, while leaks from pneumatic controllers, or valves, were pegged at more than 639,000 tons a year, roughly a third greater.
Only with such a streamlining, officials say, can the industry fix shortcomings like those in California, whose energy crisis has shown pipeline capacity to be inadequate, and in Florida, where the projected natural gas demand for 2009 is more than a third greater than the capacity of the sole existing pipeline, known as the Florida Gas Transmission.
It inaugurated what, in effect, was a third great transformation in Gaddafi's international orientation.
3.03pm GMT Brown says after his release from prison Mandela engaged in a third great campaign.
That led to a third great compromise, one that would bedevil the nation for the next 75 years.
I think we're on the verge of a third great wave of innovation.
A third great white egret chick has hatched at a Somerset nature reserve, it has been confirmed.
