WASHINGTON (Reuters) -- Fiat Chrysler Automobiles NV has agreed to pay $70 million in fines to resolve a U.S. investigation that it failed to disclose vehicle crash death and injury reports, people familiar with the matter told Reuters on Wednesday.

The settlement is expected to be announced by the National Highway Traffic Safety Administration as early as Thursday. Fiat Chrysler in September acknowledged it had failed to disclose an unspecified number of reports that are required to be submitted to regulators under a 2000 law. NHTSA in September called Fiat Chrysler's reporting omissions a "significant failure."

In July, the automaker reached a separate $105 million settlement with NHTSA over its handling of nearly two dozen recalls covering 11 million vehicles.

Major auto companies are required to electronically submit massive amounts of data involving vehicle crashes, deaths, lawsuits, warranty claims and other information.

Fiat Chrysler told NHTSA earlier this year it had problems with its software for extracting information from a company database to submit to NHTSA, and as a result significantly under-reported death and injury claims. There is no indication that Fiat Chrysler intentionally hid the reports.

NHTSA and Fiat Chrysler declined to comment on Wednesday. The sources asked not to be identified because the settlement had yet to be made public.

The early warning reports are required under the 2000 law passed by Congress after more than 270 people were killed in rollover crashes in Ford Explorers with faulty tires. The law is aimed at helping regulators spot safety defect trends earlier.

In July, Fiat Chrysler agreed to a three-year consent decree it signed as part of the $105 million settlement into its prior recalls. In October, NHTSA named former Transportation Secretary Rodney Slater to monitor Fiat Chrysler's compliance.

Slater is likely to review the company's early warning reporting as part of his oversight. Fiat Chrysler is required to conduct sweeping training and safety reforms and must hold regular meetings with NHTSA.

In January, Honda Motor Co agreed to pay a $70 million fine for failing to disclose more than 1,700 reports of deaths, injuries and other information to NHTSA. It was the largest auto safety fine in U.S. history at the time.

(Editing by Eric Beech and Matthew Lewis)