Senators are wasting no time in launching negotiations to merge the Finance Committee’s $829 billion health care overhaul bill — passed Tuesday on a 14-9 vote — with competing legislation approved by the Health, Education, Labor and Pensions Committee, with hard bargaining expected to begin Wednesday.

President Barack Obama and Senate Democratic leaders now face the arduous task of crafting a bill that can garner 60 votes, without dismantling the Finance bill’s signature achievement: a Congressional Budget Office analysis projecting that the legislation will extend health coverage to millions of Americans without adding to the federal deficit. The CBO also predicts that Finance Chairman Max Baucus’ (D-Mont.) bill will lower health care costs in the years to come.

Fresh off a victorious committee vote over a year in the making, Baucus signaled his intent to forcefully protect his bill in the merger negotiations, set to occur behind closed doors in Senate Majority Leader Harry Reid’s (D-Nev.) office. The talks will include Reid, Baucus, the No. 2 HELP Committee Democrat Chris Dodd (Conn.) and senior White House officials.

“The country wants a balanced bill,— Baucus told reporters moments after his health care reform package was reported out of Finance. “I also want to make sure that the final bill passes the CBO test and is deficit-neutral and bends the cost curve — which are very strong considerations for a lot of Senators.—

With the Finance Committee’s work complete, decisions loom for Reid and Obama.

The Finance package is rated as more fiscally sound and meets the president’s requirement for a budget-neutral bill that costs less than $1 trillion over the first 10 years. But the HELP legislation includes a robust and expensive public insurance option and is chock-full of the liberal reform priorities favored by at least half of the majority’s 60 Senators.

Several Finance Democrats who voted to report the Baucus bill out of committee said they did so to maintain progress toward enacting reform this year and in the hope that their problems with the legislation will be addressed, either in the merger or once a package hits the floor. Democratic leaders expect Obama to mediate the major disputes and make the difficult choices on the most contentious issues.

“I look forward to going further as we bring a final bill to the floor,— Democratic Senatorial Campaign Committee Chairman Bob Menendez (N.J.) said just prior to voting to report the Finance bill out of committee. “I hope we’ll get to see a public option in the final bill.—

White House Chief of Staff Rahm Emanuel and Nancy-Ann DeParle, the president’s top health care adviser, are likely to be in Reid’s office for the duration of the merger negotiations. Office of Management and Budget Director Peter Orszag is also expected to play a role. Baucus said he expects the negotiating group to remain small.

Despite moderate Sen. Olympia Snowe’s (R-Maine) vote in favor of the Finance package Tuesday, the final tally was a largely partisan affair that saw every other Republican oppose the measure, including ranking member Chuck Grassley (Iowa).

Finance Republicans cited various problems with the committee bill — including a fear that the legislation would move left in the upcoming negotiations. Meanwhile, Snowe cautioned that her favorable vote should not be “misinterpreted— as a signal that she is now on board with the Democrats’ health care reform agenda.

In fact, Snowe couched her “yes— vote similar to many Finance Democrats — as a vote for progress, not necessarily for the bill itself, although she said there is much about it she likes. “That is what my vote to report this bill out of committee today represents, to continue the process,— the Senator said.

Snowe’s support for the Finance package marked the first time this year that a Republican has voted in favor of any of the five Democratic bills that have cleared various House and Senate committees. Rather than signaling the beginning of bipartisan cooperation on health care reform, the Maine Republican’s vote to join with the Democrats is likely to remain an anomaly.

Finance Republicans on Tuesday asked several pointed questions of CBO Director Douglas Elmendorf intended to poke holes in his staff’s analysis of the Baucus bill and lay the groundwork for discrediting it.

Additionally, Senate Republicans are painting the upcoming merger negotiations as setting up a backroom deal.

“The real bill is currently being written behind closed doors in the dark corners of the Capitol,— Sen. Orrin Hatch (R-Utah) said just before voting against the Finance bill.