Sen. Edward W. Brooke (R-Mass.) and the attorney who resigned in protest from an internal Senate investigation of his finances will confront one another in a hearing, possibly later this week.

Sen. Adlai E. Stevenson (D-III.) chairman of the Senate Ethics Committee, announced yesterday that the panel voted 4 to 1 to invite both Brooke and Richard J. Wertheimer, the special counsel who quit the case last week.

Stevenson said he wasn't sure the meeting could be public because of the need to protect the confidentiality of the larger Brooke inquiry. Sen. Robert B. Morgan (D.N.C.) said he voted against the hearing Brooke requested because he feared it would "sidetrack" the committee from completing its more important investigation.

The committee has already said it could not complete the inquiry before the coming Nov. 7 election Brooke faces in Massachusetts. It seems clear that Wertheimer's sudden resignation was triggered by a belief that Brooke and his attorneys were trying to delay his investigation past the election by withholding, and he charged, altering, documents.

Stevenson said the Brooke-Wertheimer hearing will be held as soon as possible "because we owe the public an explanation."

Earlier yesterday, Brooke took the offensive at a Boston news conference, assailing Werheimer for "hit and run" tactics and saying, "I'm getting tired of being harassed by these rumors, innuedoes and outright falsifications."

This latest twist in Brooke's election-year misfortunes "obviously will have an impact on the outcome of this election," the senator said, adding later, "What its impact will be God only knows - but He's in control."

Brooke asserted, however, that the Massachusetts electorate has become jaded over the flurry of bad publiccity surrounding his bitter divorce fight during his primary campaign this past summer.

"The public is getting tired of this," he said. "I'm getting tired of it. tr for add 4

Brooke, the only black U.S. senator, faces a difficult battle in his bid for a third term against Democratic Rep. Paul E. Tsongas, a progressive liberal.

The senator indicated Wertheimer's charges and resignation were timed to be politically devastating to his reelection chances.

"This is a hit-and-run situation where Mr. Wertheimer has hit and resigned," he said. "I want an opportunity for the public to know what the facts are and I want to confront Mr. Wertheimer and say. 'Where are the alterations and where is the delay?" . . . not just hit and run off and leave me there three weeks before the election is over."

Brooke maintains that only one document was "corrected" - a check stub and a ledger entry originally listed as a $27,000 loan form Toronto insurance executive Norman Cohen. The funds, he later admitted, actually constituted a partial return on his investment in a ferry operating between Puerto Rico and St. Thomas.

The document was corrected and initialed by Brooke's office manager, Caryle Connally, at the behest of Brooke's attorneys, before it was submitted to the committee. The senator stressed yesterday that the former Ethics Committee counsel had been informed of the change as long ago as Oct. 4.

The Senate Ethics Committee investigation into Brooke's finances stems from his admitted "misstatement" about a $49,000 loan on a court deposition taken during his divorce and his failure to list that figure on his financial disclosure for the Senate.

According to Senate regulations, which Brooke had a prime role in drafting, all loans over $2,500 must be listed.

The Ethics Committee probe began 4 1/2 months ago after Brooke requested a meeting with the committee to discuss reports about his financial dealings in the press.

Brooke has maintained all along that he is guilty of no impropriety and that he has fully cooperated with committee demands for his financial documents dating back to the late 1960s.