SHANGHAI, April 14 (Reuters) - China's main indexes on Friday had their biggest loss in two weeks amid concerns over stepped-up regulation and whether an economic recovery could be losing steam.

The blue-chip CSI300 index fell 0.8 percent to 3,486.50 points, while the Shanghai Composite Index closed down 0.9 percent to 3,246.07 points.

For the week, CSI300 was down 0.9 percent and the SSEC lost 1.2 percent.

A slew of data this week, including inflation and trade, has led investors to question the sustainability of the economic recovery.

Data showed China's production price inflation starting to peak, CPI weaker-than-expected and property sales growth down sharply.

"These are definite signs that the reflation trade is fading," said Hong Hao, head of research at BOCOM International.

He added that the market had not fully priced in these changes to the world's second largest economy, partly because of suspected government intervention.

On Thursday, 14 Chinese companies suspended trading in their shares, citing the need to further evaluate the potential impact on business from plans for a new economic zone at Xiongan. Some market participants suspect the concerted moves are the result of regulators' intervention.

An index tracking major lenders posted its 5th straight session of losses, after a flurry of moves by regulators to curb riskier lending activity, including a crackdown on misdemeanours with a focus on shadow banking.

Xiong'an New Area continued to be the strongest and most eye-catching investment theme in the market, as China's government hopes the economic zone near Beijing will see the same rapid growth as a zone launched in Shenzhen in 1980.

For the day, sectors fell across the board, led by lenders and developers, as the country expanded restrictions on property investment to more cities. (Reporting by Luoyan Liu and John Ruwitch; Editing by Richard Borsuk)