TOKYO (Reuters) - Nissan Motor Co <7201.T> said on Friday it would expand an investigative recall in certain U.S. regions to replace air bags made by Takata Corp <7312.T>, adding about 45,000 Sentras from the 2004-2006 model years that weren't included previously.

Japan's second-largest automaker has informed the U.S. National Highway Traffic Safety Administration about its plans to replace passenger-side air bags of the affected Sentras, a spokesman said.

Bloomberg reported earlier the expansion followed a March 21 accident in which a woman was injured from shrapnel in her 2006 Sentra in Louisiana, which is one of the states covered in Nissan's regional recall.

Since 2008, about a dozen automakers have recalled nearly 25 million vehicles equipped with potentially deadly Takata-made air bag inflators, which can explode with too much force and shoot metal shards into occupants.

(Reporting by Chang-Ran Kim; Editing by Chris Gallagher)