Senate Banking Committee Chairman Jake Garn (R-Utah) said last night that he soon will introduce the most comprehensive legislation yet proposed to solve the economic problems of the nation's financial institutions.

The legislation that Garn is expected to propose within the next two weeks will be structured primarily to aid the the nation's financially troubled savings and loan associations.

In a statement issued by his office last night, Garn said it was clear from hearings which his committee held this spring that the way in which financial institutions conduct their business has changed "radically" within the past year.

Garn said he is confident that his legislative package "will enable the nation's financial institutions and federal regulators to cope better with the economic problems and realities of the 1980s."

While declining to discuss specific provisions of the legislation, Garn said it would cover the whole range of financial issues identified in the committee's hearings.

What's more, said Garn, his legislative proposal would be "broader and more comprehensive than any of the regulatory reform bills which have been discussed so far."

Garn's announcement of his intentions comes less than a week after Federal Home Loan Bank Board Chairman Richard T. Pratt disclosed that he and the Reagan administration are close to substantial agreement on the type of legislation they believe is needed to restructure the S&L industry.

Legislation advocated by Pratt would give S&Ls broader powers to make loans for purposes other than mortgages and would give federal regulators more flexibility in dealing with troubled institutions.

The proposal apparently is a refinement of a draft bill that the bank board had circulated on Capitol Hill a few months ago.