Shares of Singapore construction firm Yongnam Holdings <YNAM.SI> rose as much as 19% on Tuesday after two brokerages announced positive ratings on the stock.

At 9:44 a.m., Yongnam shares were trading at $0.31 on a volume of 67.6 million shares.

CIMB Research raised its target price to $0.41 from $0.39 and maintained its “outperform” rating for the firm. DBS Vickers initiated coverage on Yongnam with a “buy” rating and a target price of $0.45.

“The research reports were a factor in the rise of share price,” said a local trader, adding that there was also a spill-over effect on other construction stocks.

Chip Eng Seng <CESE.SI> was up 2.6% at $0.40 on a volume of 4.1 million shares and CSC Holdings <CSCH.SI> rose 6.1% at $0.175 with 11.3 million shares changing hands.

CIMB Research said it has raised its earnings per share estimates for Yongnam’s 2010-12 financial years by 1-2% to factor in lower revenue recognition but higher margin assumptions from specialist civil engineering projects.

The brokerage said it anticipated a flow of contract wins worth around $120 million ($91.32 million) in Yongnam’s fourth quarter this year, more than double the amount in the previous quarter, as the group is likely to win more rail way projects.