The plan by a group of Middle Eastern investors to buy control of Financial General Bankshares Inc. of Washington "cannot realistically be accomplished," the company's present management contends in a letter to be sent to shareholders today.

The letter claims it is "virtually impossible" for the takeover to succeed by July 31, the deadline set by the Securities and Exchange Commission.

If the deadline isn't met -- or extended -- the Middle Eastern Group is under court order to abandon the effort and sell its stock in the Washington bank holding company, the management letter notes.

The mailing is Financial General's formal response to an attempt by Saudi Arabian businessman Shiek Kamal Adham to elect three nominees to the company's board of directors at the annual stockholders' meeting later this month. Adham has also asked stockholders to approve a resolution recommending Financial General's management drop its opposition to the takeover.

Under the rules of corporate politics, the two sides can make their appeals to shareholders only in formal communications filed in advance with the SEC. t

Adham, former head of Saudi Arabia's intelligence agency and an adviser to the royal family, is one of three Middle Eastern investors who own about 19 percent of the stock of Financial General.The group says it is prepared to buy the rest of Financial General's stock for $25 a share; lately the stock has sold for around $17.