"largest expenditure" is correct and can be used in written English.
For example: Last year, the company's largest expenditure was for new computers.
The next largest expenditure is building maintenance, at 26percentt.
Because that's the second largest expenditure for the state, I believe.
The military remains by far the largest expenditure in Myanmar, at about 25 percent of the budget, he said.
Its largest expenditure went to the public relations firm of Burson-Marsteller, which earned about $300,000 from August 2006 to April 2007.
While Mr. Bush's largest expenditure was in California, Mr. Gore put more of his resources in Florida than in any other state.
In 2008, of a total income of £7.2m, the largest expenditure was on "public education and awareness" at more than £2.1m.
His aides said that Mr. Paterson cut the state's largest expenditures remaining in December.
In addition to the bribes — one of Yemen's largest expenditures — there is corruption.
A Major Cost In many low-income working families, child care is one of the largest expenditures after housing.
Because Medicaid is one of the largest expenditures in every state budget, and one of the fastest-growing, it makes an unavoidable target.
Over the past two decades, China has rapidly increased its spending on its public pension programs, to the point that pension funding is one of the government's largest expenditures.
