Four men, including three executives of an armored car service victimized in the nation's largest robbery, were indicted yesterday in the theft of hundreds of thousands of dollars and misappropriation of $29 million more.

District Attorney Mario Merola also hinted that somewhat less than $11 million may have been taken in the Dec. 21 robbery of the headquarters of Sentry Armored Car Courier Corp.

The heist, which has not been linked with the corporate skimming, has been listed as the largest in U.S. history. Three men, including a Sentry guard, were arrested earlier for that crime.

Indicted were John Jennings, 63, a former police lieutenant and Sentry's founder and president; Kuno Laren, 58, company chairman, and Angela Fiumefreddo, 45, vice president, as well as Jack Finnerty, vice president of the Hudson Valley National Bank of suburban Yonkers.

Allegations in the indictment include the theft of insurance monies to be paid to Sentry's clients following the holdup of Sentry trucks last year, the theft of nearly $350,000 from three Sentry clients and the manipulation of $29 million in Chemical Bank funds in 1981 in a scheme whereby the money, which was to be shipped to a federal reserve bank, was cabled to Hudson Valley so $16,500 in interest could be collected.

As for the record robbery at Sentry, Merola indicated he believed so much money was being diverted from one bank to another that there might not have been $11 million around for the robbers to steal.