Most financial institutions in the Washington-Baltimore area will begin offering higher interest rates on savings accounts starting July 1, according to an area survey.

Of 40 institutions surveyed, all but three banks said they would raise the rate from 5 percent to 5 1/4 percent. All but two savings and loan associations will increase interest rates to 5 1/2 percent. The other two are Maryland insured S&Ls and already pay 6 percent on passbook accounts.

A new four-year savings certificate is also scheduled to make its debut July 1. The small saver's version of the money market certificate will be adjusted to the Treasury's rate for a hypothetical four-year note. Banks issuing these certificates during July can pay 7.6 percent annual interest on them; thrifts can pay 7.85 percent. The rates will vary each month for new issues.

Though financial regulators placed no ceiling on the amount a person must deposit to qualify for these rates, all institutions with one exception will stipulate minimums, ranging from $100 to $1,000. Annapolis Federal Savings and Loan was the only institution surveyed that said it would be willing to pay the higher rate on whatever balance below $100 the customer wants to maintain for four years.

In general banks are asking higher minimums than thrifts. One third of the banks questioned will require $1,000, whereas 68 percent of the savings association will have a $100 - or less - minimum deposit.

Five financial institutions of the 40 surveyed said they do not plan to offer the new certificate. They are Riggs National Bank, Madison National Bank, National Capital Bank, and two savings and loans, Community and John Hanson. A Riggs spokesman said the bank saw no need for it, that its present selection of certificates of deposit was adequate.

Three others were undecided whether or when to offer the certificate or at what minimum. Two, National Bank of Washington and Standard Federal Savings and Loan, declined to be interviewed on their plans.

Several institutions said they were also reducing minimums on certificates of deposit with other maturities they offer as well. The increased rates and reduced balances are the regulators' response to demands by consumer groups that small savers be allowed to receive the same sinterest rates as large savers. A compromise was worked out whereby people depositing less than $10,000 for at least four years would receive one or 1 1/4 percent below market rates, or 7.6 to 7.85 percent this month.

The current rate for $10,000, six month money market certificates is 9 percent. The rate for jumbo certificates over $100,000 is negotiable. The Federal Home Loan Bank Board estimates that by the end of this year more than a quarter of the savings accounts held by S&Ls will be of the variable rate type.

Credit unions are also planning to offer these mini-market certificates paying 7.85 percent. The maturity, which varies between 90 days and six years, is left up to the individual credit union, as is the minimum deposit, if any.

Penalties for premature withdrawal from time deposits have been reduced for all certificates issued by banks and thrifts. Credit unions have also waived penalties altogether, provided a 90-day notice is given, on so-called notice accounts. These are new savings plans paying 7.85 percent in which the consumer deposits a regular amount each week for at least 90 days. With proper notice the entire balance can be withdrawn without forfeiting interest.

To offset the higher rates, which will cost banks and thrifts millions of dollars, the Bank Board also authorized federal S&Ls to begin offering variable rate mortgages (VRMs) starting July 1. But don't expect to see any in the Washington area for a month or more.

The interest rate on a VRM moves up or down according to changes in a cost of funds index issued by the Bank Board. The maximum increase is 1/2 percent a year or 2 1/2 percent over the life of the mortgage; there is no limit on how far the rate can go down.

Apart from possible legal and technical difficulties, the VRM presents serious marketing problems, according to Maryland Savings and Loan League president, Charles H. Kresslein Jr. Government regulations force lenders to present a "worst case" table, showing how high a customer's mortgage payments could go, and a cost of funds index for the past decade, showing how much the price of borrowed money has increased. After seeing the figures, most borrowers tend to prefer the security of a fixed rate mortgage.

These consumer safeguards have slowed efforts by federal S&Ls in California - the first state where they were offered - to promote them. Kresslein and others say VRM marketing will have to include reduced initial rates plus portability and assumability clauses. These last would permit a new buyer to assume an existing mortgage at the current rate and allow a borrower to take VRM along when buying another home.