WARSAW, May 5 (Reuters) - Several hundred miners attacked company security guards with wooden clubs and threw eggs outside the headquarters of mining group KGHM where CEO Herbert Wirth was meeting union leaders over a pay dispute.
Unions want more than the 4.6 percent rise offered by Europe's No. 2 copper miner, which sees its profit doubling this year to a record 8.4 billion zlotys ($3.16 billion).
KGHM expects its 18,500 employees' average monthly salary to exceed 9,000 zlotys, 2.5 times the Polish average, but workers want 300 zlotys a month more.
"Six security officers have been injured, one has his arm broken and being put in plaster now. We've seen clubs and eggs flying, tear gas has also appeared," company spokesman, Dariusz Wyborski, told TVN CNBC.
Broadcasts from the southwestern city of Lubin showed workers scuffling with guards, breaking glass doors to the building and men punching guards holding riot shields.
KGHM, which is highly unionised and has a long history of pay disputes, says agreeing to workers' demands would boost its already-high production costs by over 200 million zlotys.
"We are used to sirens and firecrackers. We thought it would be similar this time, but KGHM has not seen anything like this," Wyborski said.
Shares in KGHM dropped 2.2 percent to 187.30 zlotys by 1100 GMT, having topped 200 zlotys last month to push the company's market capitalisation over 40 billion zlotys for the first time. The stock weighed on Warsaw's blue-chip WIG20 index, which fell 0.7 percent.
Copper prices rose over $10,000 a tonne in February. (Reporting by Adrian Krajewski; Editing by Louise Ireland)