Ticketmaster Entertainment Inc. and its TicketsNow resale service have been sued by a customer who claims the companies impose “grossly inflated” prices for concerts.

New Jersey resident Michael Kelly claims that Ticketmaster earns “significantly higher” commissions in the secondary market through TicketsNow, according to his lawsuit in federal court in Newark, N.J.

On Jan. 24, Kelly used Ticketmaster to buy four Grateful Dead tickets with a face value of $398 and was routed to the TicketsNow website, which charged him $829.15 for seats to an April 25 show, the complaint alleges.

“Within literally moments of tickets going on sale by Ticketmaster, and often less than one minute later for high-demand events, those tickets are being offered for resale in the secondary market by TicketsNow at greatly inflated prices,” according to the May 11 complaint, which seeks group or class- action status.

The complaint came more than a month after Ticketmaster said it got subpoenas and demands for sworn information from the Justice Department and Federal Trade Commission, Canada’s Competition Bureau and New Jersey’s attorney general for information about its agreements with ticket resellers.

Hannah Kampf, a spokeswoman for Ticketmaster, based in West Hollywood, Calif., didn’t immediately return a call seeking comment. The company is the world’s largest ticket seller.

The company reached an agreement with New Jersey in February to offer as many 2,000 Bruce Springsteen tickets to two May concerts after fans complained about being steered to TicketsNow.