UPDATE 2-PBG, Polimex miss Q3 f'casts, shares underperform

* PBG Q3 net at PLN 39 mln vs 44 mln in Reuters poll

* Polimex Q3 net at PLN 33.8 mln vs 37.5 mln in poll

* Shares in PBG dip, Polimex underperforms the market

(Adds new analyst comment, updates share reaction)

WARSAW, Nov 9 (Reuters) - Poland's top two construction groups missed net profit forecasts in the third quarter, setting up a tough challenmge to meet annual targets in the typically strong fourth quarter.

PBG PBGG.WA and Polimex MOSD.WA reiterated their full-year guidance for 2009, with PBG planning to grow its bottom line by a fifth, while Polimex bracing for a 15-percent net-profit growth.

"Everything will be settled in the fourth quarter, which especially in the case of PBG has a big share in full-year results," IDM SA analyst Adrian Kyrcz said. "The targets seem doable."

PBG, which failed in a bid to take over Polimex earlier this year, grew its third-quarter bottom line by 13 percent, while Polimex eked out a 1.5 percent gain, both coming in a few million zlotys below market consensus.

Net profit at PBG, which specialises in gas, oil and water installations, stood at 39 million zlotys ($13.7 million), compared with 44 million in a Reuters poll and leaving the builder 81 million short of its 2009 target of 190 million.