The Federal Home Loan Bank board last week approved an application by Miller and Smith Holding Co. of McLean to acquire Providence Savings and Loan Association for about $17.8 million in cash.

"The acquisition means that Providence can continue to operate as a small, independent institution in an age when most small banks are being swallowed up by larger ones," said Ron Faett, president of Providence Savings and Loan.

Providence is a $180 million institution with nine offices throughout Northern Virginia. It is now publicly held, but under Miller and Smith it will become a private institution. The association's stockholders will get more than $73 per share -- or about two times book value -- at the close of the deal.

"We were not out soliciting offers, but because of our area and size we had many inquiries," said Faett. One of those inquiries came from the Student Loan Marketing Association (Sallie Mae) in the fall of 1983, but their offer did not receive approval from the Home Loan Bank board, he said.

Gordon Smith, chairman of the board of Miller and Smith, sat on the board of Providence Savings for three years before he made a formal purchase offer in July of last year. Miller and Smith is an investment firm with interests in home building, commercial real estate, land development and mortgage banking in Northern Virginia and Montgomery County.

The Federal Home Loan Bank board has taken one year to grant final approval.

Miller and Smith "knows the major players in Northern Virginia who can take advantage of services offered by Providence," said Smith.

Providence will remain independent under the agreement. It keeps its present name and personnel, including Faett. The S&L will shift from a state charter to a federal charter, a change that means little in the day-to-day business operations, according to Faett.

Providence is the eighth subsidiary and first S&L to be owned by Miller and Smith. The acquisition means Miller and Smith is taking a stronger stance in "the strongest market in the whole country," said Smith. That market is Northern Virginia.

For Providence, the acquisition means easier access to some bank operations. Providence may be able to offer FHA-VA type loans through the McLean Mortgage Co., a subsidiary of Miller and Smith. Faett also expects loan servicing to be more efficient because Providence and McLean Mortgage can process their loans through the same portfolio.

But Smith warned that federal regulations forbid Miller and Smith and its subsidiaries from working too closely with Providence. For example, Providence cannot make loans or provide other banking services to Miller and Smith Holding or its subsidiaries.

Smith and Faett agreed that the acquisition would bring new Providence branches to Northern Virginia. "We want to improve branch operations and be a little more aggressive about opening new branches," said Smith. The thrift does not have formal expansion plans yet.

Versar Inc. of Springfield recently signed a letter of intent with ARIX Corp. to acquire all of its capital stock in exchange for Versar Inc. common stock valued at about $3.5 million.

The acquisition of ARIX Corp., based in Greeley, Colo., will take Versar into the Rocky Mountain region. Now the company has offices on the East Coast, plus one in Chicago and two in California.

Versar and its subsidiaries, Geomet Inc. and ETA Inc., research environmental health and safety problems caused by pollutants, hazardous materials and toxic substances. ARIX Corp. is involved in the same field from an engineering and architectural standpoint.

"ARIX compliments what we do," said Dr. Robert Ouellette, vice president of corporate communications for Versar. Geomet finds contamination problems, ETA finds regulation problems, and "Geomet finds a way to fix the problems," said Ouellette. ARIX does this by designing structures that discourage contamination and hazardous waste.

Versar "wants to be the one-stop shopping center of environmental agencies. The acquisition of ARIX is more step towards that goal," said Ouellette.

The acquisition is expected to close by early August, subject to the approval of each company's board. ARIX will not change its name or restructure its personnel. Gary Windolph will remain president of ARIX.

Dupont Ventures Systems recently offered to purchase Systems Technology Associates Inc. of Sterling. Dupont's offer includes a share for share trade, according to Thomas Coletti, account executive at Brooks Winger public relations firm.

S.T.A. makes electronic equipment used in the international telephone and telegraph industry. Its products include electronic switching equipment necessary for automatic international direct dial telephone and telegraph services and devices to adapt existing telephone and telegraph centers to international requirements.

Dupont Ventures is a Philadelphia holding company with one subsidiary, Synergistics Technology Inc. Synergistics makes a special anti-friction coating that can replace oil in automotive parts and other machinery.

S.T.A. has been looking for a buyer for the past month, according to James White, chief operating officer of S.T.A. The company's revenue dropped from $2.5 million in 1985 to $1.7 million in 1986.

Com-Site International Inc., a privately held technology firm in Beltsville, recently acquired Vatec Inc. of Laurel for an undisclosed price.

Com-Site designs and builds large data centers for companies such as Intelstat, Citibank and Blue Cross/Blue Shield, and for various government agencies. The company studies the needs of its clients, then builds and completely outfits a data center.

Vatec Inc. is involved in the security aspects of data center construction. It has equipment that recognizes the hands or the eyes of employes before admitting them to the site, and devices to prevent outsiders from tapping into computer information.

"Vatec gives us one more vantage point in the market," said Ahmad Abediyeh, director of corporate communications and international affairs for Com-Site.

Vatec now operates as an affiliate of Com-Site, but retains its name and its president, Frank Schroeder. Vatec will coordinate efforts with other subsidiaries of Com-Site to serve clients, said Abediyeh.