Senate leaders yesterday broke a partisan stalemate that had halted all action for a week, agreeing on an artfully crafted plan for four days of debate and votes early next month on legislation to regulate managed-care health plans.

The accord also paves the way for a vote on the confirmation of Lawrence H. Summers to succeed Robert E. Rubin as treasury secretary before Congress leaves later this week for a week-long Fourth of July recess, according to Majority Leader Trent Lott (R-Miss.). Lott previously warned that Summers's nomination might be held up if the stalemate continued.

The agreement came after Democrats repeatedly refused to allow votes on a farm spending bill or any other legislation until the Senate's Republican majority agreed to permit votes on key elements of the Democrats' version of the politically popular "Patients' Bill of Rights."

Republicans mounted a counterattack, accusing the Democrats of "obstructionist" tactics and insensitivity to farmers. But they faced protracted deadlock, threatening progress on must-pass appropriations bills, so long as the Democrats held firm. And, through a series of votes Monday, the Democrats showed no signs of backing off.

The situation underscores the degree to which the Senate's minority party can use the rules to force a reluctant majority to consider its agenda, sometimes with success. Three years ago, Democrats used a variety of tactics, including periodic shutdowns of Senate business, to force votes and eventual approval of a minimum wage increase.

Yesterday's agreement, announced by Lott and Minority Leader Thomas A. Daschle (D-S.D.), calls for debate on the health care measure to begin July 12, the day that Congress returns from recess, and conclude with a vote on final passage July 15.

It differed from earlier Republican offers by including time limits that Daschle said would ensure consideration of most, if not all, of the 20 amendments that Democrats want to offer. The GOP also dropped a prohibition on further action on the issue later in the year.

By dropping what Democrats described as a "gag rule" to bar further votes, the agreement assured Democrats of further recourse if Republicans block consideration of their proposals. But Republicans said they would not do so, and Daschle said he had no intention of staging a rematch if Republicans play fair.

With the Republicans controlling the Senate by a 55-to-45 majority, Democrats acknowledge their bill would lose out in a head-to-head contest with a narrower and less regulatory GOP version. But they insist that some of their specific proposals, such as one empowering doctors rather than HMO officials to decide what treatment is necessary, could pass if presented on their own. Republicans have been reluctant to allow such votes, arguing that Democrats want them mainly to force GOP lawmakers to take embarrassing votes before next year's elections.

"This is a great victory for the 160 million Americans [who belong to managed care and other private insurance plans] who are demanding that Congress act," Daschle told a news conference.

Republicans emphasized that the Senate is back in business and dismissed suggestions of a Democratic victory. "Democrats are finally going to take yes for an answer," said Lott spokesman John Czwartacki, referring to the agreement's similarity to aspects of earlier Republican offers.

Lott said he hopes the Senate will be able to approve three to five appropriations bills before the recess.

CAPTION: Senate Majority Leader Trent Lott said the agreement will allow the Senate to confirm Lawrence H. Summers as treasury secretary this week.