As the Massachusetts House and Senate finalize bills to provide $1 billion for life sciences research over the next decade, university presidents within the state are urging legislators to leave the division of the funding to a panel of experts.

University President Drew G. Faust joined MIT President Susan Hockfield, a biologist, and University of Massachusetts President Jack M. Wilson­, a physicist, in co-authoring a letter to the legislature last month that underscored the need for funding to remain flexible as research develops.

The letter, which the presidents wrote as co-chairs of the Massachusetts Life Sciences Collaborative, emphasized that the state should take a “less prescriptive approach to programs and investments” in order to “achieve the necessary coordination and flexibility.”

The life science plan is the brainchild of Mass. Gov. Deval L. Patrick ’78, who proposed it last year as a means to ensure the long-term competitiveness of Massachusetts’ vaunted life sciences industry. California, for example, which has a burgeoning biotechnology sector of its own, is devoting $3 billion to stem cell research over the next 10 years.

In the bill that Patrick filed last year, the bulk of the $1 billion was to be appropriated by a panel comprising academics and industry experts. But the two versions of the bill that have been winding through the House and Senate have already tied down virtually all of the $500 million that is devoted to capital projects.

In a story on Tuesday, The Boston Globe reported on the significant restrictions in the bill and said that the letter by the presidents was a direct criticism of the legislative earmarking.

But Kevin Casey, Harvard’s associate vice president for government, community and public affairs, said yesterday that the letter only says that the universities would like to leave “some portion of the research [dollars] to be allocated for discretionary review.”

Casey said that the legislature should give more authority to the Massachusetts Life Sciences Center, which was created to coordinate the state’s efforts in the life sciences. This, he said, would ensure that all of the funds are not “allocated today, but can be adaptable to current trends as we see them emerge.”

Casey added that Harvard is not as interested in the $500 million designated for capital projects—95 percent of which is already locked down in the House bill—but on the $250 million in research grants for which the University’s researchers could be eligible. The remaining $250 million is for tax-breaks geared toward industry.

Two of Harvard’s west coast competitors in the biomedical sciences—Stanford and the University of California at San Francisco (UCSF)—have already received significant infusions from their state’s stem cell initiative.

In its first round of awards last month, California gave $44 million to Stanford for its $200 million stem cell institute and $35 million to UCSF for its $95 million research center.

Because there is little federal funding available for stem cell research, Harvard’s own $100 million institute was funded largely with private funds.

The Massachusetts bill has already passed both the House and the Senate and is currently in conference committee. Legislative leaders hope that the two versions of the bill will be reconciled in the next few weeks so that Patrick can sign it before attending the BIO International Convention, a major biotechnology conference that is being held in San Diego next month.

Patrick had announced the $1 billion plan at the 2007 BIO International Convention, which was held in Boston last May.

—Staff writer Nathan C. Strauss can be reached at strauss@fas.harvard.