LONDON (Bloomberg) — British Airways pilots will vote whether to strike in protest over plans by the carrier, Europe's third-largest, to start a subsidiary in continental Europe.

Pilots are concerned that workers at the new carrier will be hired on contracts different from those at British Airways, the British Airline Pilots Association said yesterday in an e-mailed statement. Balpa, which represents most of the airline's 3,200 pilots, said industrial action would mark the carrier's first strike by pilots since 1980.

London-based British Airways is starting a subsidiary called OpenSkies to fly to the US from Paris or Brussels under a new air-services treaty. The airline will need a lower cost base than the primary business, chief executive officer Willie Walsh told reporters on January 9.

"We believe that the company could use OpenSkies as a Trojan horse to bring down pay and conditions at BA mainline," Balpa spokesman Keith Bill said yesterday in an interview. Having two separate groups of pilots also will "diminish the BA brand" and threaten safety standards, he said.

The open-skies accord allows European Union airlines to fly to the US from any of the bloc's nations instead of just their home countries, from March 31. The British Airways subsidiary will fly to New York starting in June using one Boeing Co. 757 plane. It plans to have six aircraft by the end of 2009.

"We are disappointed that Balpa has confirmed its intention to ballot its members for industrial action," British Airways said in a statement yesterday. "We have given Balpa assurances that OpenSkies will have no detrimental impact on BA pilots."

The union will ballot pilots over the next three weeks, Bill said. The organisation is required to give the airline seven days' notice of any action, so the earliest a strike could take place would be in about a month, he said.