UPDATE 1-BMW recalls 150,000 vehicles for airbag sensor fix

(Recasts with comments from BMW spokesman)

FRANKFURT Aug 14 (Reuters) - BMW (BMWG.DE) will recall around 150,000 vehicles in North America to fix a possible defect that may keep the front passenger airbag from opening in a crash, the world's biggest premium carmaker said on Thursday.

The voluntary recall concerns the front passenger airbag seat sensor mat in certain 2004-2006 model year vehicles, a company spokesman in Munich said.

U.S. traffic safety regulators had referred to 200,000 such vehicles, but the spokesman said 50,000 of them had already received new mats that function properly.

"It is definitely only a problem for the U.S. and Canadian markets," the spokesman added, noting those two countries required sensors to detect if a baby seat or a grown person was occupying the passengerseat.

Models affected include certain 2006 3-Series, 2004-06 5-Series and 2004-06 X3 vehicles.

BMW said it would start sending letters to customers in late September and that affected owners could continue to drive their vehicles unless the airbag warning lamp and the passenger airbag 'on-off' lamp illuminated simultaneously.

"In this situation, BMW recommends customers not to use the front passenger seat and have the vehicle serviced immediately. At the present time, we are unaware of any accidents or injuries as a result of this issue," it added in a statement.

The spokesman said BMW procured the sensor mats from the VDO automotive electronics business that Continental AG (CONG.DE) bought last year from Siemens (SIEGn.DE).

"We don't want to blame them. It is something we will solve in September," he said.

He said he could not comment on the potential financial impact of the repairs but added: "We have it under control."

BMW shares slipped 1.3 percent to 28.85 euros by 0900 GMT -- hit in part by a Citigroup downgrade to "sell" -- while the DJ Stoxx European car sector index .SXAP edged up 0.3 percent. (Reporting by Michael Shields; Editing by Erica Billingham)