A moderately weaker yuan is not likely to provide much of a lift to China's struggling export sector, though persistent weakness in the yuan may stoke speculation of other nations devaluing their currencies too to bolster economic growth.

The median forecast of 23 analysts showed the yuan is forecast to slip 0.98 percent to 6.4500 against the dollar in the next 12 months, down from Wednesday's close of 6.3870.

Estimates ranged from a 5.6 percent rise to a 8.8 percent drop.

Chinese brokerage Haitong Securities was the most bearish and thought the yuan, also known as the renminbi, could slide to 7.0000 in a year's time. In contrast, Canada's Scotiabank predicted the currency could rise to 6.0500 in 12 months' time.

Economists at Haitong argued the yuan rose an average 3.5 percent a year between 2005 and 2013, and had jumped as much as 7 percent in 2007 and 2008.

"Today, the yuan's depreciation is the exact opposite," Haitong said, adding the currency could fall by around 2 percent in the coming year. "In an extreme case, it could depreciate by around 5 percent."

The results of the poll conducted after the devaluation contrast with a Reuters poll last week that forecast the yuan would trade at 6.21 per dollar in a month and 6.20 in six months and 12 months.

In a move couched as deepening China's financial reforms, the central bank said on Tuesday it was changing the way it calculates the official daily guidance rate for the yuan, and that the switch involves a "one-off depreciation" of about 2 percent.

Despite its rise as a global currency, the yuan is tightly controlled by China, which sets a daily fixing from which the yuan can rise and fall at most two percent on each trading day.

Some institutions, however, interpreted the move as a precursor to a further slide in the yuan to shore up growth in China's flagging economy.

A run of poor economic data from exports to investment and factory output this month suggested the cooldown in the world's second-largest economy may have worsened despite four interest rate cuts since November.

Indeed, some government researchers and advisers say China's currency devaluation this week reflected a clamor in Beijing to weaken the yuan to boost exports, and that it was likely for the yuan to fall further in the months ahead.