Boston — Call it a clash of the state's gambling titans.

The middle-aged Massachusetts State Lottery is nervously looking over its shoulder to see if the state's newborn casino industry will drain away some of the hundreds of millions it generates in profits each year for local cities and towns.

While the lottery was poised to sell nearly $5 billion worth of tickets for the just-ended 2015 fiscal year — a record for the four-decade-old institution — the moneymaking machine is scanning the horizon for signs of casino encroachment.

Lottery officials said they're not only monitoring for any dip in sales of lottery tickets around the new betting venues but are also looking for ways to improve on lottery products as they compete for gambling dollars.

"We're really looking at this as an opportunity, as a chance to review all our products," said Michael Sweeney, interim executive director of the Massachusetts State Lottery. "We see this as a very healthy challenge."

Sweeney said the lottery has already zeroed in on the just-opened Plainridge Park Casino in Plainville, the state's first gambling facility under the 2011 casino law. Sweeney said the lottery is monitoring weekly lottery sales within a 15-minute, 30-minute and hour radius of the slots parlor and is working closely with its agents, including the mom and pop convenience stores that sell lottery tickets.

The lottery is also invading the casinos themselves, as allowed by the casino law.

Lottery tickets are on sale at the Plainridge gift shop. Keno is offered at two locations there, including Flutie's Sports Pub. And the lottery placed five vending machines that sell scratch tickets and also tickets for draw games like Mega Millions.

In its last fiscal year without casino competition, the lottery tallied more than $4.97 billion in sales as of June 27, a record that topped the $4.86 billion it took in the previous year.

Lottery profits — which are sent to cities and towns in the form of unrestricted local aid — are estimated at $935 million for the fiscal year that ended Tuesday.

In an interview with the Associated Press earlier this year, state Treasurer Deb Goldberg, who oversees the lottery, said she's also keeping a close eye on casinos.

"When people ask me what I think of local gambling, what slots or casinos will do, I say it doesn't matter whether it's 1 percent or it's 10 percent. Any percent that is an impact takes away from my ability to send money back to cities and towns," she said.

Not everyone sees casinos as a threat to the lottery.

Massachusetts Gaming Commission Chairman Stephen Crosby said the 2011 casino law was written to protect local aid.

He pointed to a section of the law that requires 100 percent of the revenue the state receives from the Plainridge slots parlor be transferred to a local aid fund — estimated at anywhere from $85 to $120 million each year.

For the full casinos, at least 20 percent of state revenues from the facilities will go to the same local aid fund.

"It is highly likely that local aid will go up as a result of the introduction of casinos, not go down," Crosby said.

Geoffrey Beckwith, executive director of the Massachusetts Municipal Association, said local aid "should be increasing for the foreseeable future."

Exactly how much of a dent casinos could put in lottery revenues isn't clear.

Crosby and Sweeney both said past experiences in other states and locations around the world suggest any slowdown in lottery sales would be slim.

In Pennsylvania, where the first of 12 casinos opened in 2006, sales of lottery tickets have remained generally strong.

Research released in March by a legislative study agency concluded that "the overall growth of lottery sales over the last four years indicates that any impact of casinos on lottery sales is, at most, marginal."

In Ohio, video lottery machines housed at seven racetracks are run by the state. The popularity of the machines has helped drive a steady increase in lottery profits even as money from traditional games has fallen. Casino gambling legalized in 2009 appears to have had little impact on the lottery's profitability.