Allied Capital Corp. declared a quarterly dividend of 25 cents per share, payable Sept. 30 to stockholders of record Sept. 16 . . . Maryland National Bank declared a quarterly dividend of 34 cents per share, payable Sept. 30 to stockholders of record Sept. 15 . . . A. H. Robins Co. declared a quarterly dividend of 17 cents per share, payable Sept. 9 to stockholders of record Aug. 24 . . . F&M National Corp. declared a quarterly dividend of 17 cents per share, payable Sept. 30 to stockholders of record Aug. 26 . . . Central Fidelity Banks Inc. has approved a three-for-two split of the company's common stock. This action is contingent upon approval by CFB shareholders of a proposal recommended by the board of directors to increase the number of authorized common shares to 20 million shares.

In addition, the board set a new quarterly dividend rate of 25 cents per share of common stock payable on the new shares outstanding if the shareholders approve the proposal to increase the number of authorized shares. The cash dividend after the issuance of the additional shares will represent an increase of 10.3 percent over the previous quarterly dividend and is payable Oct. 1 to stockholders of record Sept. 21. If the proposal is not approved and the stock split not effected, a cash dividend of 37 1/2 cents per share will be paid on the same date on the number of shares outstanding. The special shareholders meeting is scheduled for Sept. 9 for stockholders of record Aug. 4.