Carmelo Anthony of the New York Knicks and football's Manning brothers are among the new investors in SeatGeek, a search engine for sports and entertainment tickets.

Joining Mr. Anthony's Melo7 Tech Partners and Peyton and Eli Manning in the $35 million Series B round are Causeway Media Partners, a $135 million sports-focused investment fund led by Boston Celtics owner Wyc Grousbeck, rapper Nas, Stanford University athletics, Seattle Mariners co-owner and Real Networks founder Rob Glaser and National Basketball Association veterans Shane Battier and Mike Dunleavy, Jr., the company said Thursday in a news release.

The financing was led by Accel Partners, whose partner, John Locke, will join the SeatGeek board.

The money will help SeatGeek bolster its team, expand its product and accelerate growth via marketing, the company said.

"They will probably be the leaders in mobile ticket solutions," Mr. Grousbeck said in a telephone interview, describing his fund's investment as "sizable," though "much smaller than Accel."

"It's a question of letting people know it's out there—acquiring more users by marketing," he said.

SeatGeek, which began in 2009, said it expects to drive more than $160 million of ticket sales this year. The New York-based company said it's on pace to drive $13 million in sales this month, a 50% increase over July.

SeatGeek's mobile applications have been downloaded almost 2 million times, the company said, adding that mobile transactions are growing at a 70% rate month over month.