Gov. D. Robert Graham is expected to decide today whether to veto a sweeping revision of Florida's banking code because of a provision that would ban loan competition by large out-of-state banks.

The present banking code will expire automatically next Monday under a "sunset" provision. If Graham vetoes the new legislation, the action could leave the state with no banking code at all. However, Florida's comptroller and banking commissioner, Gerald Lewis, said he still would have considerable general authority to regulate financial institutions.

Graham objects to a provision in the bill, passed by the 1980 legislature, which would prohibit out-of-state bank holding companies from opening "loan production offices" (LPOs) in Florida. The Florida Bankers' Association pressed hard for the provision, which was designed to keep down competition from such banking giants as Citicorp of New York and Bank of America of California.

Graham calls the prohibition "anticompetitive." He said the clause is a "monopolistic response" to competition and a "signal to people outside of Florida that this state is not serious about its commitment to economic development and diversification."

Graham also believes the ban is unconstitutional under a recent ruling by the U.S. Supreme Court in the so-called Bankers Trust case. There, the court invalidated a Florida prohibition against trust advisory offices established by out-of-state banks. The court said it was a violation of the commerce clause of the U.S. Constitution, and Graham believes the language of the ruling is broad enough to apply to the LPO prohibition as well.

Florida's new banking code is one of a package of five bills passed by the recent legislature, replacing the expiring code and related statutes.

Along with the LPO ban which Graham opposes, a veto also would:

Strike down authority to charter any new state banks.

Prohibit present Florida banks from opening any new branches.

Probably open the door to state banks in other states to start new branches in Florida.

Lewis has advised Graham that a veto would not lead to chaos in Florida banking because other laws give him sufficient regulatory authority to get by, at least for a short time.

Lewis said he has been assured by the Federal Deposit Insurance Corp. that federal insurance will continue in force on all Florida deposits with or without the new banking code.

Although the legislature passed the package of new banking bills well before adjournment June 11, the House speaker deliberately held up the banking code bill. He sent it to the governor only after adjournment, thus confronting Graham with a dilemma: either sign the bill, or veto it and call an expensive special session to remedy the problem, or veto it and let the state do without a banking code at least for the time being. Another possible course of action is to sign the bill, relying on the Supreme Court ruling to make the LPO ban inoperative.

Late today, Graham was reported leaning toward a veto.