(New throughout, adds comment from Exxon, further comments from attorney general)
BOSTON, April 13 (Reuters) - Massachusetts' top court on Friday rejected Exxon Mobil Corp's bid to block the state's attorney general from obtaining records to investigate whether the company for decades concealed its knowledge of the role fossil fuels play in climate change.
The Massachusetts Supreme Judicial Court ruled Attorney General Maura Healey had jurisdiction to seek records to probe whether the oil company's marketing or sale of fossil fuel products violated the state's consumer protection law.
The ruling marked another setback for Exxon after a federal judge in March dismissed a related lawsuit it filed seeking to block investigations by Healey and New York Attorney General Eric Schneiderman, both of whom are Democrats.
Exxon argued that because it is incorporated in Texas and New Jersey, Healey had no basis to issue a demand for documents in 2016 to conduct a Massachusetts-based investigation of whether it misled consumers and investors.
But Justice Elspeth Cypher, writing for a 6-0 court, said jurisdiction existed because of Exxon's control over advertising conducted for about 300 franchise gas stations operating under the Exxon and Mobil brands in Massachusetts.
She said Healey's probe related to how manmade greenhouse gas emissions had caused climate change, "a distinctly modern threat that grows more serious with time, and the effects of which are already being felt in Massachusetts."
Healey said she hoped Exxon would now turn over documents it has fought hard against disclosing, showing what it knew about climate change and when it knew it.
"I hope this decision will encourage Exxon to end their scorched earth campaign," she said.
Scott Silvestri, a spokesman for Exxon, said the company was considering its next steps.
Healey and Schneiderman launched their investigations following news reports in 2015 saying Exxon's own scientists determined that fossil fuel combustion must be reduced to mitigate the impact of climate change.
Those reports by InsideClimate News and the Los Angeles Times were based on documents from the 1970s and 1980s. Exxon contended that the documents were not inconsistent with its public positions.
Exxon has called the investigations politically motivated and in a separate lawsuit filed in federal court claimed that Schneiderman and Healey were conspiring to "silence and intimidate one side of the public policy debate."
But U.S. District Judge Valerie Caproni in Manhattan dismissed that case in March, rejecting as "implausible" Exxons' claim Healey and Schneiderman were pursuing bad faith investigations in order to violate its constitutional rights. (Reporting by Nate Raymond in Boston Editing by David Gregorio and Bill Trott)