With five days left before a deadline, about 1,800 District retailers that operate weighing and measuring devices have not yet registered them with the city as required under a new law, according to the D.C. Department of Consumer and Regulatory Affairs.

The businesses, which include grocery stores and service stations, must register the devices with the agency by Oct. 1. The District passed a law earlier this year designed to protect consumers from malfunctioning or inaccurately calibrated product scanners and measuring tools, such as meat scales and gasoline pumps.

The agency has sent notices to 2,000 District businesses advising them of the new law, but only 205 have registered their devices.

* Forbes magazine released its annual list of the 400 richest Americans, including 11 in the District, Maryland and Virginia. The District's wealthiest were Mitchell P. Rales and Steven Rales of Danaher Corp. Forbes said each has a net worth of $1.9 billion, ranking 118.

Maryland's richest: B. Francis Saul II of Chevy Chase, $900 million, No. 340; Marriott International Chairman John Willard Marriott Jr. of Potomac, $1.2 billion, No. 234; Host Marriott Chairman Richard Edwin Marriott, $1.4 billion, No. 203; Allegis Group Chairman and Baltimore Ravens owner Stephen J. Bisciotti of Severn Park, $850 million, No. 352.

Virginia's richest: Mars Chairman John F. Mars, $10 billion, No. 17; Forrest Edward Mars Jr., $10 billion, No. 17; former America Online chairman Stephen M. Case, $825 million, No. 363; former Landmark Communications chairman Frank Batten Sr., $1.3 billion, No. 215; and Winnie Johnson-Marquart, part of the family that founded S.C. Johnson & Sons and president of the Johnson Family Foundation, $1.5 billion, No. 165.

VIRGINIA

* Builders in Northern Virginia filed a complaint Friday with the State Corporation Commission against the electric cooperative that serves more than 120,000 homes and businesses in Clarke, Fairfax, Fauquier, Loudoun, Prince William and Stafford counties, the city of Manassas Park and the town of Clifton, asking the agency to stop the utility's plan to require builders to install the electrical facilities underground.

The Northern Virginia Building Industry Association cited unacceptable job safety risks and an unnecessary increase in new-home prices in asking the SCC to enjoin the Northern Virginia Electric Cooperative from implementing the policy. Builders estimate the new policy could add as much as $6,000 to the average cost of a home in the co-op's service area.

MARYLAND

* Advancis Pharmaceutical of Germantown said it expects to begin advanced human testing next month on a new formulation of the antibiotic amoxicillin. The formulation relies on the company's Pulsys technology to reduce the number of doses and the amount of antibiotic administered while maintaining concentration levels to kill bacteria.

* American Capital Strategies, which invests in small businesses, announced that it had priced its public offering of 11.5 million common shares at $31.60 per share. The company plans to use $73 million from the direct sale of 2.5 million common shares to reduce its debt and to fund investments.

* Federal Realty Investment Trust bought two supermarket-anchored shopping centers in the Boston area for $38 million. The two properties, Campus Plaza in Bridgewater, Mass., and Pleasant Shops in Weymouth, Mass., were acquired for the Trust's recently announced joint venture with Clarion Lion Properties Fund from a private owner.