The former president of a Washington firm, Export-Import. International, has been arrested as a fugitive in New York on two-year-old fraud charges, the U.S. attorney's office here said.

Arrested at John F. Kennedy Internationl Airport after questions arose about the validity of a passport he presented was David Kosoy, 61, formerly of 1900 Lyttonville Rd., Silver Spring.

Kosoy was charged in a federal indictment here in May 1977 with defrauding the First National Bank of Washington of $30,000. The Indictment was routinely dismissed earlier this month because of the lenght of time Kosoy was a fugitive. But prosecutors said the charges were reinstated yesterday in an arrest warrant filed in New York.

According to investigators, Kosoy obtained a loan from the Washington bank by using as collateral a promisory note of $40,000 from a prominent Washington real estate dealer.

However, investigators said when Kosoy did not pay back the loan and the bank attempted to collect the money from the realtor, its officers discovered that the realtor had already paid Kosoy the $40,000 even before Kosoy had put up the note as collateral. Kosoy then fled, and is believed to have been living in his native Argentine, investigators added.