(Reuters) - While the volume of lawsuits under a federal robocall law is expected to sharply decline after a U.S. Supreme Court ruling last week in favor of Facebook Inc, the era of Telephone Consumer Protection Act litigation still isn't over, attorneys said.

There are still narrow avenues for consumers to pursue lawsuits against businesses under the TCPA, both through components of the law the high court decision did not address and parts of the ruling that could be open to interpretation, plaintiffs' and defense lawyers said.

"The TCPA took a hit, but it is not dead," said Christine Reilly, who leads the TCPA compliance and class action defense practice at Manatt, Phelps & Phillips.

Companies in a wide range of industries have faced lawsuits under the TCPA, which places restrictions on certain calls and texts to consumers, and some have paid millions in class settlements. Defense lawyers said companies should take a close look at what the high court decision does and doesn't do and to still be vigilant about compliance with the law.

"I expect that the TCPA will continue to be a thorn in the side of every sector of American business," said Eric Troutman, a class action defense partner at Squire Patton Boggs who focuses on the TCPA. While there will be a "reduction in litigation," he said, "companies that are not cautious with TCPA compliance are just going to get hit with a different kind of lawsuit."

In a unanimous decision authored by Justice Sonia Sotomayor, the court addressed the 1991 law's definition of an automatic telephone dialing system, concluding that to qualify as an autodialer, equipment must have the "capacity to use a random or sequential number generator to either store or produce phone numbers to be called." The narrow interpretation will make it easier for many businesses to call or text consumers without consent.

Defense and plaintiffs' lawyers said that the decision is likely to stave off significant litigation, as a large share of lawsuits have focused on autodialer use. But they still anticipate individual and class action TCPA lawsuits, albeit a smaller volume, alleging violations of restrictions on artificial and pre-recorded voice calls and for dialing numbers on the Do Not Call registry – issues that the high court decision did not reach.

Beyond that, attorneys pointed to aspects of the autodialer component of the law that may be up to interpretation in lower courts going forward. For one, the high court's April 1 decision didn't address the role of the word "capacity" in the autodialer definition, attorneys said, and lower courts will have to continue to grapple with that in litigation.

Several attorneys also pointed to a footnote in the Supreme Court ruling that, if read in a certain way, could offer plaintiffs a window to pursue some autodialer claims. Footnote seven in the decision says an autodialer "might use a random number generator to determine the order in which to pick phone numbers from a preproduced list," to store the numbers to dial at another time.

That could potentially be interpreted to sweep predictive dialers, or calling systems that dial lists of numbers and connect agents when a person answers, under the law, two plaintiffs' lawyers said.

The lawyers didn't go so far as to say they personally will be pursuing claims with that interpretation of the footnote.

Abbas Kazerounian, a founding partner of Kazerouni Law Group, said he will be "taking a very close look" to see the applicability of the footnote to predictive dialers in litigation. Morgan & Morgan consumer protection head Octavio Gomez also said the footnote "does open up a door."

In the short term, lawyers said they will be looking at their existing cases to see how they fit into the decision. Generally, going forward, Kazerounian and Gomez said some plaintiffs' attorneys will still bring TCPA cases, but they will be very selective about which ones to bring and in which jurisdictions.