This is the story of two bar associations with similar names and similarly stated aims, but with vastly different resources in members and money. As may be expected in situations like that, there is a simmering feud between the two that sometimes threatens to break into open warfare.

One is the Bar Association of the District of Columbia, a 107-year-old organization of about 4,700 lawyers who join it because they want to. It once ruled the roost of Washington legal organizations; anyone who was anyone in the city's legal establishment belonged.

The other is the 6-year-old District of Columbia Bar, which all 26,000 Washington lawyers must join whether they want to or not in order to practice law here. It is an arm of the D.C. Court of Appeals created to make sure that all Washington lawyers are subject to the same disciplinary rules, but with a wide-ranging charter that enables it to get into almost any legal area it wants to.

And that's the rub. There is strong sentiment among some Washington lawyers that the D.C. Bar has expanded into areas it should stay out of.

The current dispute centers on the lawyers referral service just started by the D.C. Bar. The D.C. Bar touted the referral service at a press conference as a unique program designed to make it easier for people to get legal aid at a price they can afford.

The Bar Association cried foul. Eugene Ebert, head of its lawyer referral program, says the program has provided that service since 1956. He called the new D.C. Bar program "a duplicate of our service. Why did they duplicate something that is in existence already?" he asked.

His answer: "I think it is a competitive thing. I just have a feeling there is a little battle going on. If we do something, they will do it too, and probably do it better because they have the money."

There is no question that the competition has improved the Bar Association's service. Until recently, according to its ad in the classified telephone directory, it was open only from 10 a.m. to noon and 2 to 4 p.m. Newspaper ads this month however, listed its hours from 9 a.m. to 5 p.m. - the same as the D.C. Bar's referral service.

Paul Carlin, an attorney who works for the D.C. Bar and set up its referral service, is happy to join battle with Ebert. He said he tried to cooperate with the Bar Association's program and would have like to merge the two, but ran into a stone wall.

"There's no other referral service in the country that has all the features of ours," he said."They had a service for 20 years, and now they feel a little bit threatened. We felt that more should be done."

And members of the Bar Association, known among lawyers as "the voluntary bar," have good reason to feel threatened. As the number of Washington lawyers has grown, so has the D.C. Bar's membership and dues income - which is now more than $1 million a year, as a result of changes in the admission rules, about 5,000 new lawyers have joined and will add between $100,000 and $160,000 in dues money.

While the D.C. Bar is rolling in money, the Bar Association is having financial problems. As one indication, it is trying to sell its 50,000-volume law library, currently kept in the U.S. District Courthouse. Informal appraisals, said Bar Association Past President John P. Arness, put its value at $500,000 if sold in crates to book dealers and $1 million if sold intact to a library.

There are only a limited number of law schools or other institutions who would want to buy the library whole, and the Bar Association has been negotiating with the D.C. Bar - a move that Arness favors "because I'd like to see it kept here."

The D.C. Bar is polling all its members, via a ballot in its magazine, The District Lawyer, for their views on establishing a law library and where it should be located - at the courthouse or downtown. The ballot estimated that either starting its own library or buying the Bar Association's would add $10 to $15 a year for 10 years to yearly dues. That includes not only the cost of the books, but maintaining the library.

Arness called the Bar Association's library unique and said it contains material of historial importance that even the Library of Congress does not have. This includes bound volumes of all decisions of the U.S. Court of Appeals here since the court was founded.

Back home again. Warren G. Elliott, who worked here from 1955 to 1968 both on Capitol Hill and in private practice, has returned to Washington. He resigned as general counsel for Aetna Insurance because "more lawyering and less managing would better suit my taste" to become a partner in the Washington firm of Hedrick and Lane.

Also joining the firm as a partner is Larry Merthan, who had been executive vice president of the Carpet and Rug Institute and before that a senior vice president of Hill and Knowtion, one of the largest public relations companies in the world. Merthan has also worked for Eugene McCarthy when he was a senator from Minnesota.

Merthan and Elliot have worked closely together before. Merthan was handling, among other things, Health Insurance Association matters for Hill and Knowtion - trying along with Aetna to block a labor-sponsored bill that would cut private companies out of any national health insurance plan.

The firm has also taken on Gene Thore, who was president of the Life Insurance Association of America when Elliot was one of its Washington lawyers, and promoted to partner Filmore E. Rose who had been an associate.

John Lane, who founded the firm 25 years ago with Cleve Hedrick, said it is no major expansion - just filling some vacancies created when young associates left.

Short takes: Charles Halpern, who left Arnold & Porter to head the Council for Public Interest Law and then taught law at Stanford University, is coming back to Washington. He will teach at Georgetown University Law School and run the Institute for Public Interest Representation there . . . Surprise. Here's one leaving town. Allen Morrison is leaving the litigation branch of the Ralph Nader conglomerate, Public Citizen, to teach at Harvard Law School for a year. He'll teach administrative law from the unique perspective of someone who thinks it works against the public and a course in professional responsibility (define it as legal ethics) that will give views on the economics of the legal system not generally heard from Harvard Law School podiums.

The D.C. Bar's nominees to its Board on Professional Responsibility are Allen R. Snyder, Girardeau A. Spann and Marcia Devins Greenberger. Their names have been forwarded to Chief Judge Theodore R. Newman Jr. of the D.C. appeals court, and the court will select one of the three.