WASHINGTON (Reuters) - Mazda Motor Corp (>> Mazda Motor Corp) said Friday it will recall 374,000 U.S. vehicles linked to potentially defective front passenger- side airbags made by Takata Corp (>> Takata Corporation).

The Japanese automaker said the latest recall was prompted after Takata said testing showed additional airbag inflators could be prone to ruptures. The expanded recall includes the 2003-2008 Mazda6, 2006-2007 MazdaSpeed6 and 2004 RX8.

Takata airbag recalls are linked to nine deaths and more than 100 injuries stemming from airbag inflators that ruptured and sent metal fragments flying.

The airbag safety recalls are among the largest in U.S. automotive history, encompassing 23 million air bag inflators in 19 million vehicles manufactured by 12 car companies.

Last month, the National Highway Traffic Safety Administration said Honda Motor Co Ltd (>> Honda Motor Co Ltd), Fuji Heavy Industries Ltd's (>> Fuji Heavy Industries Ltd) Subaru unit, and Mazda would add thousands of vehicles to the massive recall campaigns based on additional inflator testing.

Honda said it was adding 127,000 2003-2004 Honda CR-V. The expanded callbacks also include the 2005-2008 Subaru Legacy and Outback.

NHTSA said last month that a quarter of vehicles recalled have been fixed, including a third of vehicles in high-humidity areas, where automakers believe the risk is highest for ruptures. But that leaves around 15 million vehicles unrepaired.

In November, Takata agreed to pay a $70 million fine for safety violations and could face deferred penalties of up to $130 million under a NHTSA settlement.

(Reporting by David Shepardson; Editing by Lisa Shumaker)