NEW YORK (Reuters) - JPMorgan Chase & Co <JPM.N> said that demand for its high-fee, high-rewards Sapphire Reserve credit card is "strong, but tapering" and that the cost of opening new card accounts could hurt fourth-quarter revenue by as much $200 million.

JPMorgan made the disclosures in a quarterly filing on Tuesday after the stock market close.

The Reserve card, which carries a $450 annual fee but offers more than $1,300 in credits and give-backs on new accounts, has been surprisingly popular and escalated competition between card issuers for customers.

(Reporting by David Henry in New York)