Banks in the Washington area will be open Friday for the July Fourth holiday weekend because of a ruling by the Federal Reserve Board.

The decision to keep banks open Friday is part of the Federal Reserve's effort to create uniform bank holidays when national holidays fall on weekends. For some time, banks have closed on Mondays when a national holiday falls on a Sunday. But there was no clear standard when the holiday fell on a Saturday.

Under the new rule, when a national holiday falls on a Saturday, banks probably will stay open on the preceding Friday. If a bank doesn't, its decision probably will cost it money.

The incentive for banks to stay open on Fridays is the board's decision to have its 12 regional banks remain open on those Fridays. Any bank that belongs to the Federal Reserve system that closes voluntarily will risk having to pay interest charges on checks that have been processed by the Fed that cannot be credited immediately to customers.

The Federal Reserve Board of Governors notified banks about the new policy in March. The new standardized Fed calendar is consistent with "generally accepted industry practice," said Joseph Coyne, a spokesman for the board of governors. Coyne said the Federal Reserve made its decision after surveying member banks.

But the change caused consternation for some banks in Virginia, many of which already had announced that they would be closed Friday because of the July Fourth holiday weekend.

In December 1986, the Virginia Bankers Association distributed a letter to its member banks listing July 3 as a bank holiday. Many bank's followed the association's lead, according to association Vice President for Communications Bobbie Garrett.

"When we saw the Federal Reserve's calendar and noted the absence of July 3rd, we spent a great deal of time reviewing our situation," said John Sponski, Corporate Executive Officer and head of operations for Virginia's Sovran Bank.

Virginia has declared July 3 a legal holiday. The new policy exempted states from paying float charges for unprocessed checks if state law mandates banks to close on days that the Federal Reserve banks are open, said Garrett. Virginia law, however, does not obligate financial institutions to close on legal holidays.