The Reagan administration has decided against pushing for new real estate and insurance powers for banks, focusing instead on persuading Congress to grant banks permission to underwrite securities, a top Treasury Department official said yesterday.

"If you count the votes, they're not there" for allowing banks to sell insurance and real estate, George D. Gould, Treasury undersecretary for finance, told the House Banking Committee.

Gould said Congress should first revamp the 1933 Glass-Steagall Act, which separated the banking and securities industries after the 1929 stock market crash and the wave of bank failures in the Great Depression.

He said the ability of well-capitalized securities firms to weather the most recent stock market downturn provides evidence that bank subsidiaries, provided they are separately capitalized and their failure will not endanger depositors' money, also could successfully underwrite securities.

"We should discount the self-serving advice of the naysayers who will argue that the recent volatility in the stock market precludes the need to update our antiquated banking laws," he said.

Gould pointed out that state-chartered banks that are not members of the Federal Reserve system have been permitted to underwrite securities and "not a single incident has been documented where these activities ... have raised safety and soundness concerns."

In the Senate, Banking Committee Chairman William Proxmire (D-Wis.) released a summary of a bill he said he would introduce in the next week.

The bill would permit deregulation only through a holding company, which would own both a banking subsidiary and a separate securities subsidiary.

Banking regulators, such as Federal Deposit Insurance Corp. Chairman L. William Seidman, say the holding company structure would be needlessly expensive and would permit the securities activity through a direct subsidiary of the bank.

Gould sided with that view, telling the House committee, "individual managements should have the opportunity to choose the appropriate and most efficient operating structure for conducting new activities."

However, Kenneth A. McLean, staff director of the Senate Banking Committee, said Proxmire believes "it would be impossible for the bank as a practical matter to step aside and let a {direct} subsidiary fail."

"That's crucial for Sen. Proxmire. ... He believes {former Treasury} Secretary {Donald T.} Regan was right in 1984 when he said it would be unsafe and unsound for a bank to directly own a securities subsidiary," he said.