A passion for gambling shared by two once-inseparable octogenarian sisters has ended up dividing them, with the Connecticut Supreme Court ruling that one can sue the other for a share of a winning $500,000 lottery ticket.

The court said 83-year-old Theresa Sokaitis, of Middletown, can try to enforce a written contract she signed with her 87-year-old sister, Rose Bakaysa, of Plainville, agreeing to split any gambling winnings.

Sokaitis says she is due a share of a $500,000 Powerball jackpot won by Bakaysa and their brother, Joseph F. Troy Sr., in 2005.

"We had an accountant, we had a contract and we had a notary public," Sokaitis said. "We signed the contract together and we agreed to split anything. And when it came time, they didn't even tell me; I saw it in the paper."

A lower court dismissed the suit under a Connecticut law that makes gambling contracts illegal. But the high court, in a ruling that took effect Tuesday, said the sisters' agreement isn't covered by that law because it involves legal activities. It said the case could go to trial.

A message seeking comment was left Tuesday with Troy; a number couldn't be found for Bakaysa.

Sokaitis said she and her sister used to gamble together frequently, play the same lottery numbers, and play the slots and cards at the Foxwoods Resort Casino, she said.

"Almost every day, I'd pick her up, and we'd go riding around," she said. "We went to the casino a lot, and we always shared everything."

Sokaitis said they decided to put the agreement in writing in 1995 after she won more than $160,000 playing poker at Foxwoods and split it with Bakaysa.

"They actually sat down with typewriter and typed up this four-line agreement which says that 'we will share in any future winnings from lottery, cards, bingo' and actually had this agreement notarized," said Sokaitis' attorney, Sam Pollack.

But at some point the two had a falling out. Sokaitis said she doesn't remember whether that happened before the lottery ticket was bought.

But Bakaysa's attorney, William J. Sweeney Jr., said a falling-out between the two in 2004 ended the contract, and the two haven't spoken since then.

"Our position has been that if the statute as written should be repealed, then it should be repealed, but it is on the books and it should be enforced," Sweeney said. "The court has said otherwise, so be it."

Sweeney said he still believes the contract is not enforceable and will make that case at trial. Pollack argues that the contract is both legal and binding.

"Just like all siblings, there were disputes," he said. "I don't think there was ever anything that amounts to a legal rescission of this contract."

Sokaitis said she doesn't want to drag her sister into court but believes she and her family are due a share of the money.

"I miss her so much, and I love her, and I don't like what's taken place," Sokaitis said. "But all I want is what is rightfully mine. All I want is my share, nothing more."