Anna Nicole Smith's daughter Dannielynn named heir

File photo shows Anna Nicole Smith arriving for her hearing at the Supreme Court in Washington in this February 28, 2006 file photo.

LOS ANGELES (Reuters) - A judge on Tuesday ruled that the baby daughter of deceased model Anna Nicole Smith is the sole heir to her estate, meaning 18-month-old Dannielynn could inherit a multimillion-dollar fortune.

Los Angeles Superior Court Judge Mitchell L. Beckloff's ruling also established a trust for Dannielynn that would be administered by Smith's companion, Howard K. Stern, and Dannielynn's father, Larry Birkhead.

Smith, a former Playboy model and television actress, died in February last year of an accidental overdose of prescription drugs, roughly five months after Dannielynn was born. Smith's son, Daniel, died only three days after Dannielynn's birth. He was 20.

Daniel had been Anna Nicole Smith's heir according to a will that was written well before his death, but the actress/model never changed the will. Stern, who is executor of Smith's estate, had petitioned the Los Angeles court in October to name Dannielynn as the sole heir.

"We and Mr. Stern always believed that Anna Nicole never intended to disinherit her daughter," Stern's lawyer, Bruce Ross, said after the hearing. "I'm pleased to say this chapter in the saga is closed."

At the time of her death, Smith was embroiled in a legal battle over the will of billionaire oil tycoon Howard Marshall.

She married Marshall when she was 26 years old and he was 89. He died 14 months later with a fortune estimated at $1.6 billion, triggering a battle between Smith and Marshall's family over his estate that still has not been resolved.

If that dispute is settled and Anna Nicole Smith's estate receives a large payout, the money would belong to Dannielynn.

The birth of Dannielynn and deaths of Daniel and Anna Nicole Smith were the subjects of a huge media frenzy last year due to the actress/model's celebrity.

(Editing by Dan Whitcomb and Sandra Maler)