The phrase "argument for extending" is correct and usable in written English.
It can be used when discussing reasons or justifications for prolonging a certain situation, policy, or agreement.
Example: "The argument for extending the deadline was based on the need for more comprehensive research."
Alternatives: "case for prolonging" or "justification for extending".
There is an argument for extending this service to the wider public sector.
"There is an argument for extending the program because it's better to err on the side of aggression," Mr. Hayes said.
"The government's primary argument for extending the ability to collect communications data is that somehow there is a shortfall," he said.
Altogether, though, "The Spirit Level" is a garden of very unearthly delights and an excellent argument for extending the life cycle of the artist-organized group show.
The court would also have latitude to reject challenges "that are not warranted by existing law or consists of a frivolous argument for extending, modifying or reversing existing law or for establishing a new law", and to impose contempt of court penalties for noncompliant companies.
One argument for extending free school meals was that it would abolish any stigma for children from low income families.
Owners of an about-to-expire copyright have several favorite arguments for extending it.
Arguments for extending the tax credit a second time are just beginning.
The G.O.P.'s arguments for extending the Bush tax cuts to this crowd, usually wrapped in laughably hypocritical whining about "class warfare," are easily batted down.
For example, they figure prominently in the arguments for extending Title IX requirements for equal opportunity in education to science training programs (Rolison 2000, Zare 2006), that had, in the past, chiefly been applied to inequities in support for women's sports.
In his speech, Mr. Obama said the White House pushed for an extension of the payroll tax cut, in part because it anticipated that gas prices might go up – a rationale that did not figure prominently in the administration's arguments last year for extending the tax cut.
