The Middle-sex County district attorney announced yesterday that he lacks jurisdiction to prosecute Sen. Edward W. Brooke (R-Mass.) on possible perjury charges stemming from his admitted "misstatements" under oath during his divorce trial.

"We could have argued it here, but it would have been dismissed and we would have been laughed out of court," said John Kerry, an assistant district attorney speaking for District Attorney John J. Droney. "It's like hunting an animal - you want to shoot to kill, not wound."

Droney, whose office conducted a four-week investigation into possible criminal prosecution against Brooke, pitched the case back to Middlesex probate Judge Lawrence T. Perera. Droney suggested the case be referred either to state Attorney General Francis X. Bellotti or Suffolk County (Boston) District Attorney Garrett Byrne.

Byrne and Bellotti declined comment yesterday pending word from the judge. Perrera said he expects to refer the matter to Byrne.

"I had hoped it would have ended today," Brooke told United Press International when questioned in the Massachusetts secretary of state's office where he had gone to file his candidacy papers in his re-election battle. "But I'll have to respect the district attorney's decision.

["It was a question of jurisdiction, I understand. I'll just have to wait and see how it goes from here," he said.]

The complicated question of jurisdiction in this case focuses on a May 12, 1977, court deposition, a sworn statement in which, Brooke later admitted, he did not tell the truth.The false testimony was taken in the Boston law office of the attorney for his estranged wife, Remigia, during the couple's acrimonious divorce.

Although the case was pending here in Middlesex County, jurisdiction more appropriately comes under the Suffolk County district attorney because the deposition was taken in Boston, said Richard Kelley, Middlesex County assistant district attorney in charge of priority prosecutions for the grand jury.

He noted that it was not filed here in Middlesex Probate Court until the judge reopened the divorce case recently to determine whether the senator had misled his wife about his financial condition.

In a June 15 ruling, Perera decided against initiating the civil contempt proceedings, referring the matter instead to Droney. However, he gave Mrs. Brooke the option of a new divorce trial because of the senator's false testimony and conflicting financial statements. She has indicated she will accept.

The judge is set to hear motions Thursday by Mrs. Brooke for the new trial. Brooke has countered by appealing the decision granting his wife a new trial.

Both actions followed a breakdown two weeks ago in negotiations by attorneys for the Brookes on a new divorce settlement that would have headed off a new and potentially politically devastating trial.

While political opposition mounts to Brooke's bid for a third term because of reports related to the divorce, he has stepped up his campaign, telling voters his "unfortunate" problems are personal and that he is guilty of no improprieties in public life.

Those problems, including the investigation into possible perjurycharges, stem from what he termed a "misstatement" in the deposition about a $49,000 loan he testified came from a friend, Massachusetts liquor distributor A. Raymond Tye.

Brooke later conceded the Tye loan was only $2,000 and the remainder of the funds caem from his mother-in-law.

His wife claims that money was not a loan and that Brooke listed it to inflate his liabilities so that she would receive a smaller settlement in the divorce.

The $49,000 loan, meanwhile, was never disclosed on Brooke's Senate financial statement and the ethics committee is currently investigating the matter.