The sale of New Haven-based NewAlliance Bank to First Niagara, a Buffalo, N.Y. bank, will not go through without public hearings.

On Wednesday, state banking commissioner Howard Pitkin announced a two-day public hearing on Mar. 8 and 9 to review the $1.5 billion sale, which Mayor John DeStefano Jr. and Sen. Richard Blumenthal LAW ’73 have tried to prevent. DeStefano wrote to the banking commission in December asking it to use its regulatory authority to stop the deal, which he said would be a disaster for borrowers in New Haven.

“I believe that all citizens should be given the opportunity to voice their opinions related to this issue,” Pitkin said in a press release.

The deal, which has already resulted in 230 layoffs in New Haven and Manchester, Conn., will result in reduced access to credit for New Haven residents, DeStefano said in January.

Also on Wednesday, First Niagara announced that it would sign on as a sponsor of the New Haven Open at Yale tennis tournament. DeStefano told News 8 Wednesday that he thinks the sponsorship is no coincidence: First Niagara is trying to “buy some good will right now,” he said.

If approved, the merger is expected to close in April.

Correction: February 18, 2011

Due to an editing error an earlier headline of this post did not reflect the nature of the article.