Few of the area's commercial banks will begin offering the 7.75 per cent interest rate on retirement plans that savings institutions give, an informal Post survey of 17 local banks revealed.

Two months ago, the Federal Reserve Board approved a rate increase for the commercial banks, from 7.5 to 7.75 per cent, effective today, in order to increase the banks' share of the retirement funds depostis. A Fed survey taken in 1976 showed that thrift institutions held 28 per cent of the Individual Retirement Account (IRA) and Keogh deposits, while commercial banks had 10 per cent.

United Virginia Bank said it is offering 7.75 per cent on both IRAs and Keogh plan deposits for a minimum of three years, while Suburban Trust plans to do so only on six-year certificates.

National Savings & Trust in the District and Union Trust of Maryland said they would offer the higher rate on IRAs only. Union Trust does not handle Keogh plans, while NS&T channels its Keogh clients' requests for certificates of deposits through savings and loan associations already paying the premium rate, spokesmen said.

Seven other banks queried said they would not raise interest rates, although two of those qualified their remarks by adding "not for the moment."

K. Donald Menefee, executive vice president of the Madison National Bank, added, "We cannot put away money profitably at that rate." He said Madison will stick to the 5 per cent passbook rate.

Americans now have over $4 billion invested in these self-retirement plans, but pension experts estimate less than 10 per cent of the 40 million individuals who are eligible have set up accounts.

Other requirements for the plans that have limited participation in the past were also done away with by the Fed in order to increase the market. The board eliminated a minimum denomination requirement for the savings certificates and wiped out penalty provisions for premature withdrawal in case of death or disability.

The new rules, the Fed says, should allow Keogh participants to increase retirement savings by up to $500,000 if they contribute the maximum allowed 30 years; IRA savings could hit $10,000.

Under Keogh, an individual can put away up to 15 per cent of his net annual income tax-free, up to $7,500-IRA rules permit a 15 per cent maximum deposit of gross earnings up to $1,500 a year.