But Chrysler said it will not decide whether to expand the regional recall, as requested by U.S. safety regulators, until next week.

In a letter sent on Tuesday to Chrysler, the U.S. National Highway Traffic Safety Administration said the automaker must expand the recall and begin notifying customers of the action by Dec. 1.

Chrysler's delay in alerting owners of potential defects in the Takata air bags "exacerbates the risk to motorists' safety," the NHTSA said in a Nov. 25 letter to Chrysler Chief Executive Officer Sergio Marchionne.

Chrysler, a unit of Fiat Chrysler Automobiles, was among 10 automakers that in June began recalling vehicles registered in some high-humidity states and U.S. territories because the Takata air bags in those vehicles can rupture and spray metal shards into occupants.

Ruptured inflators in Takata air bags have been linked to at least five deaths in Honda Motor Co cars since 2004.

In June, Chrysler recalled 371,000 Chrysler and Dodge vehicles from model years 2005 to 2008 with the air bags. In a September memo on the regional recalls that was made public last month, NHTSA estimated that Chrysler would need to replace the air bags in about 441,000 cars.

NHTSA Deputy Administrator David Friedman said "Chrysler is obligated" to expand its recall to coastal areas of Texas, Louisiana, Mississippi and Alabama as well as southern Georgia, Guam, Saipan and American Samoa. Takata had sent NHTSA a report on Nov. 10 that said its air bags in those areas were defective, he said.

So far, Chrysler's recall has only covered Florida, Puerto Rico, Hawaii and the U.S. Virgin Islands.

Takata told NHTSA it will begin shipping replacement parts to Chrysler on Monday.

Chrysler said on Wednesday that it now plans to begin notifying owners on Dec. 8, rather than Dec. 19 as it earlier planned. Chrysler officials will review a possible expansion of the recall on Dec. 2, the automaker told NHTSA.

(Reporting by Bernie Woodall; Editing by Lisa Von Ahn, Jonathan Oatis and Lisa Shumaker)

By Bernie Woodall