* Bogdanka shares surge 20 percent to 107 zlotys
* Market expects NWR to sweeten deal of 100.75 zlotys/share
* Aviva OFE says valuation of Bogdanka well above NWR bid
(Releads with Aviva comments)
By Adrian Krajewski and Patryk Wasilewski
WARSAW, Oct 6 (Reuters) - The top shareholder of Poland's miner Bogdanka rejected a $1.2 billion takeover offer by its larger rival NWR on Wednesday, fueling speculations of a higher bid.
Hopes that Dutch-registered NWR, controlled by Czech mogul Zdenek Bakala, would need to sweeten its offer have pushed Bogdanka shares 20 percent higher to an all time-high of 107 zlotys, well above the 100.75 zlotys per share bid announced on Tuesday.
If successful, the combination would create a regional coal powerhouse worth some $5.6 billion with annual production of 25 million tonnes, NWR said in its presentation.
"We appreciate NWR's management drive to increase the value for its shareholders," said Pawel Klikowski, an equity fund manager at pension fund Aviva OFE, which with 15 percent of Bogdanka is its largest shareholder.
"However, our valuation of Bogdanka shares is significantly higher than the one proposed by NWR," he said.
NWR declined to comment.
Several other pension funds that became Bogdanka's main shareholders when Poland sold its remaining 47 percent stake to them in March either declined to comment or were not available.
Bogdanka said it was looking at detailed information about the bid.
"The management board will take a position on the offer in due course," Bogdanka said in a statement on Wednesday.
Analysts said NWR would benefit from the deal because of Bogdanka's strong results and stable long-term contracts coupled with an ambitious expansion programme.
Bogdanka's shares rose 17.95 percent to 107 zlotys by 1509 GMT, while the Warsaw index was 0.2 percent higher. Shares in NWR were 3.27 percent higher at 217.90 Czech korunas, and the Prague index was up 1.2 percent.
Last week, the Polish miner said it expected its full-year profit to rise 5 percent to 201 million zlotys ($71 million), having previously forecast no change to its 191 million zlotys profit in 2009.
NWR owns two smaller mines in Poland, but has struggled with rolling out production there.
The offer is conditional on NWR securing at least 75 percent of its rival as it wants to delist the smaller group. (Additional reporting by Jason Hovet; Editing by Chris Borowski) ($1=2.846 Zloty)