"maintain trend" is correct and usable in written English.
You can use it to refer to keeping a trend going or continuing in the same pattern as it has been. For example, "The sales team worked hard to maintain the positive trend in sales."
The teetering Indian airline industry lost an estimated $2.5 billion in the quarter ending in March 2012, according to the Center for Aviation, a research organization that maintains trends and forecasts about the aviation industry.
Would Labour maintain this trend?
Big changes often come bunched together, so that when good things are happening it is important to maintain the trend.
But there are serious doubts about whether India can maintain the trend, or accelerate it, as economists have urged.
The results maintain the trend seen in the previous quarter, when Google bucked the market by posting increased year-on-year profits.
"Sea level has been rising and it appears it will maintain that trend or even increase because of global warming," Mr. Tanski said.
In a preliminary statement, Britain's largest retail bank, said it would see a profit in the first quarter and expected to maintain the trend through the year.
They maintain the trend "came out of nowhere – it wasn't linked to any data research", but that it probably did contribute to the rise of fashion journalists "copying and pasting" trends they see on the internet.
In a preliminary statement, Lloyds, the largest consumer bank in Britain, said it would report a profit in the first quarter and expected to maintain the trend through the year.
She added that the challenge now was for police services to maintain the trend for arresting fewer children.
