Sean J. Daniels, 43, of Philadelphia and Los Angeles, an attorney and Internet entrepreneur, died Tuesday, March 24, of complications from cancer at Cedars-Sinai Medical Center in Los Angeles.

A native of Villanova, Mr. Daniels graduated from Haverford School in 1990, from Duke University in 1994, and the University of Pennsylvania School of Law in 1997.

He worked at the law firm Dewey Ballantine in New York City and became an executive director of business affairs and development for AOL in Los Angeles.

His third job was as director of the public company i3 Mobile Inc. The firm offered Pronto, a mobile subscription information and communication service designed for phones in the United States. i3 Mobile was acquired by another company in 2003.

For the last 11 years, Mr. Daniels has been a consultant for Internet businesses.

A big sports fan, he traveled often between the East and West Coasts to attend Eagles and Phillies games and to watch Duke's Blue Devils play basketball.

"He only lived 43 years, but in those years, he lived life to the fullest," said Robert A. Rovner, a former Pennsylvania state senator and longtime family friend. "He was just a fine young man. He loved Philadelphia, and in L.A., he was rooting for the Phillies. He never married, but he was a good, loyal friend."

Mr. Daniels was a member of the Squires Golf Club and contributed to various charities.

His father was Robert C. Daniels, a Pennsylvania Superior Court judge and chancellor of the Philadelphia Bar Association who died in October 2011. His brother is Christopher Daniels, a Montgomery County District Attorney.

Surviving, besides his brother, are a sister, Samantha Daniels; three nephews; and a niece.

Services were Sunday, March 29.

Contributions may be made to the Robert C. Daniels Foundation for Cancer Research, P.O. Box 18, Villanova, Pa. 19085.