Chalk one up for the shareholders of Cerbco Inc. This small but angry group of investors apparently has prevented George and Robert Erikson from selling their controlling interest in Cerbco for $6 million -- or $24.24 a share.

The Erikson brothers announced last week that their tentative agreement with Insituform of North America Inc. (INA), which wanted to buy the Erikson shares in Cerbco, had expired and that negotiations had ceased. The Eriksons also said that they had "no further intention of pursuing the proposed sale of their controlling interest to INA."

That was good news to the investors, who had complained that while the Eriksons were going to get $24.24 a share for their controlling interest in Cerbco, other shareholders were getting nothing. Indeed, Cerbco shares were trading at only $3 when the deal was announced six months ago and have since dropped to $1.75.

One of the stockholders who was pleased by the demise of the Erikson deal was Bonnie Wachtel, a vice president of Wachtel & Co., a small Washington brokerage firm that owned about 18,000 shares. The firm's clients owned another 20,000 shares. Wachtel said the episode showed that "the minority shareholders were not asleep."

Wachtel had objected vigorously to the proposed sale when Cerbco held its annual meeting in July. She was not alone.

Opposition also came from Merle Thorpe Jr., an attorney associated with Hogan & Hartson of Washington. Thorpe is head of the Foundation for Middle East Peace, which owned 5,000 shares of Cerbco. Thorpe himself owned 17,300 shares.

Thorpe challenged the proposed sale of the Eriksons' shares both at the meeting and in the Delaware courts, where the case is still pending.

Attorney Joseph M. Hassett, also of Hogan & Hartson, said he was pleased that the deal had been dropped. "We have achieved the principal thing we wanted -- that they do not do the deal," he said. However, he added, that did not mean the litigation would automatically cease. Hassett said he wanted more information about what was happening.

At Cerbco, Robert Erikson said he could not discuss the decision to drop the sale because of the ongoing legal actions.

However, at the annual meeting, Robert Erikson, who has spent 18 years at Cerbco, strongly defended his right to sell his controlling stock at a premium price.

Thus, it is far from clear what, if anything, will happen next at Cerbco.

Cerbco is a small firm located at Baileys Crossroads in Virginia. The company has three parts: an old defense contracting division that is being sold; a copying machine company; and a controlling interest in another company called Insituform East Inc. of Landover, Md.

Although the arrangement is a bit complicated, this is how it works: The Eriksons control Cerbco. Cerbco, in turn, controls Insituform East. Thus, the Eriksons, in effect, control Insituform East.

Insituform East is a company that repairs sewer pipes without digging them up, and there are a number of similar firms around the country. One of them is the Memphis-based Insituform of North America. INA wanted to buy the Erikson shares to get control of Insituform East, believing it would be a good business deal.

Whether INA is still interested in pursuing the acquisition could not be determined because company officials could not be reached. It has been suggested that INA's goal could be accomplished if the $6 million were distributed on a pro rata basis to all shareholders. It might even be possible for INA to simply buy the Insituform East shares now owned by Cerbco.

However, the first idea would not give the Eriksons the kind of money they had hoped for. The second idea would take away Cerbco's main asset -- the Insituform shares. The latter also might make life complicated for the Eriksons, who are paid executives of both Cerbco and Insituform East.

Meanwhile, Cerbco shares closed Friday at $1.75, while Insituform East shares closed at $2.87 1/2.

The turnaround is coming at Hechinger Co., Washington's do-it-yourself retailer. But it is coming slowly, says analyst Kenneth M. Gassman Jr. of Wheat, First Securities Inc. in Richmond, who thinks the company's efforts to increase its profit margins won't be fully evident until 1991.

After years of steadily rising earnings, Hechinger ran into a buzz saw in the fiscal year that ended last January, with profits down 32 percent, even though sales were up 21 percent. There were various culprits, including a reorganization of the way Hechinger ordered and organized its goods, the creation of the new Home Quarters warehouse concept stores in the Boston market and some unfavorable weather for outdoor work.

For the fiscal year, ending next January, Gassman is looking for profits to rise 7.6 percent on sales growth of 17 percent.

However, the big growth should come in the following year, ending January 1992, Gassman believes, and he foresees a 37 percent leap in profits on a 24 percent rise in sales.

In the short term, however, Gassman said, Hechinger will face a soft retail market, along with several potential problems associated with the development of the Home Quarters stores.

Gassman noted that Hechinger shares, which closed at $8.25 Friday, are selling well below the company's $11.26 book value per share.

That fact, Gassman said, "should protect {the shares} from significant near-term downside price risk. Further," he said, "based on our projected sales and earnings growth rates for the next three years, Hechinger shares are conservatively priced, in our opinion."

For investors interested in stocks in this region, there is a new quarterly report called the "Mid-Atlantic Review," which is prepared by analyst Michael L. Mead, a vice president at Legg Mason and Co. in Baltimore. Mead came to Legg Mason from Scott & Stringfellow in Richmond.

Mead's regional review covers Maryland, Virginia, the District, Pennsylvania, Delaware and North Carolina. The first issue profiles 22 companies but only one has a No. 1 rating, meaning purchase. The others are rated 2s (hold) or 3s (the stocks can be sold if funds are needed for other investments). None are rated as 4s, which means sell.

The single purchase recommendation is for United Dominion Realty Trust Inc. of Richmond, a company that specializes in buying and renovating apartment buildings.

Although it may seem unusual to recommend a real estate stock when real estate is in the doldrums, Mead notes that the 1986 tax act has caused a drop in apartment construction each year since. As a result, he said, slower apartment construction will lead to higher rents and higher future dividends on United Dominion shares.

Mead said the company, whose shares sell at $14.25 and yield 8.7 percent, should see future dividends grow at 6 percent to 8 percent a year.

Meanwhile, United Dominion is buying back up to 581,000 shares, or about 5 percent of its 11,621,000 shares. During the past 52 weeks, the price has ranged from $19 to $14.

James Dolphin, senior vice president at United Dominion, said his company's underlying assets have been estimated at between $19 and $21 a share.

Speaking of buybacks, here are two more:

Loyola Capital Corp., the Baltimore thrift, recently bought a block of 82,000 shares of its own stock for $9.75 a share from an individual investor. As of June 30, Loyola had a $28.42 a share book value, without any goodwill. The purchase was part of Loyola's buyback program, under which it purchased 200,000 of its shares last year. This year, it has bought 209,000 of 300,000 shares authorized for a second round of buybacks. Loyola had 5 million shares outstanding when the buybacks began. During the past year the stock has sold as high as $19.375.

Computer Data Systems of Rockville has authorized the repurchase of up to 200,000 shares -- about 7 percent of the 2,827,000 shares outstanding. The stock is selling at $8, having traded at between $13.87 1/2 and $7.25 in the last year.