By DENISE LAVOIE, AP Legal Affairs Writer

BOSTON (AP) — Former Massachusetts Treasurer Tim Cahill has insisted that he approved $1.8 million in state lottery ads “for the best interests” of the lottery, not to help boost his faltering 2010 gubernatorial campaign.

Cahill spent nearly two and a half hours on the witness stand Thursday at his corruption trial being questioned by his lawyer. The trial ended for the day before he could be cross-examined by prosecutors.

Cahill is charged with conspiracy to use his official position to gain an unwarranted privilege and conspiracy to commit procurement fraud.

His former campaign manager, Scott Campbell, is being tried on similar charges.

Cahill was expected to continue testifying Friday.