Farr, Miller & Washington said Sheldon S. Cohen, a former commissioner of the Internal Revenue Service, has joined the District-based money-management firm as a director and is to advise clients on tax issues. Cohen, who previously was with the law firm of Morgan Lewis & Bockius, served as IRS commissioner from 1965 to 1969.

Danaher, a toolmaker based in the District, said a subsidiary agreed to acquire 10.7 percent of the shares in DKK-TOA, a Japanese manufacturer, for about $5 million. DKK-TOA is a maker of lab and analytical instruments for environmental markets, particularly water quality.

Carlyle Group, through a subsidiary, acquired SS&C Technologies of Windsor, Conn., which provides software to the financial-services industry, for $942 million in cash.

Interstate Hotels & Resorts of Arlington bought the 195-room Hilton Durham hotel near Duke University in North Carolina for $13.3 million from MeriStar Hospitality, also of Arlington.

Cardinal Bank of McLean said it has signed an agreement to acquire some assets and assume deposit liabilities from FBR National Trust, a subsidiary of Friedman, Billings Ramsey Group of Arlington. The bank did not provide details of the transaction.

FTI Consulting of Annapolis, which provides consulting services to companies, banks and law firms, agreed to acquire Competition Policy Associates for about $70 million in cash and stock. The company being bought, known as Compass, is an economic consulting firm that provides analysis in antitrust disputes, mergers and acquisitions and policy debates. It has offices in the District and San Francisco.