WASHINGTON — U.S. Sen. Frank Lautenberg, a multimillionaire New Jersey businessman and liberal who was called out of retirement for a second tour of duty in Congress, has died at age 89.

A Democratic aide today confirmed the death of the New Jersey senator.

Lautenberg had health problems in recent years. A bout with the flu caused him to miss the Senate’s Jan. 1, 2013 vote to avoid the fiscal cliff of rising taxes and falling government spending.

He had been diagnosed in February 2010 with lymphoma of the stomach and underwent chemotherapy for the next few months.

He was principal sponsor of a law banning smoking on domestic airline flights.