The FAA said it began the administrative proceeding to determine whether the Port Authority of New York and New Jersey would violate federal regulations if it enforces its Aug. 4 proposal to bar airlines from using takeoff and landing slots at John F. Kennedy, LaGuardia and Newark Liberty international airports if the slots were acquired by auction, the agency said in a news release.

The FAA is scheduled to auction two slots once allotted to now-bankrupt EOS Airlines at Newark Sept. 3.

The U.S. Department of Transportation also announced two proposed rules earlier this year that, if finalized, would auction several takeoff and landing slots at the three airports.

Airports receiving federal grants are required to provide airlines with nondiscriminatory access to their facilities.

If the Port Authority's proposal discourages access, it may lose eligibility for either FAA grants or payments under current grants until the matter is resolved. The FAA could also issue an immediate cease-and-desist order.