Reprinted from yesterday's late editions

The Olney Theatre has inaugurated its 1980 summer season with its costomary opener -- an Agatha Christie mystery play. And, as is usual for these opening productions, some of the liveliest scenes come at intermission.

On a June evening in the Maryland countryside, the audience for "A Murder Is Announced" gathered in small groups at intermission to consider the question: "Who do you think did it?"

"I think it's the maid because no one else qualifies as the butler," argued one of the opening-night viwers.

In "A Murder Is Announced," Dame Agatha, tha English gentlewoman, who dispatched her victims with wily and devious cunning to confound a legion of mystery readers, had laid down a trail of tantalizing clues -- a sealed door with well-oiled hinges, a frayed light cord, mysterious pasts, a fortune waiting to be inherited, a question of identities, and a Swiss connection. By the end of Act I, nearly everyone is an obvious suspect.

If "A Murder Is Announced" is not on a level with such Christie stage classics as "Witness for the Prosecution" and "The Mousetrap," it does have its perplexing and entertaining moments. Dame Agatha, a master of the sleight-of-hand in planting clues, supplies a puzzler that unravels to reveal a most satisfactory least likely culprit. And she does play fair with the audience if they pay attention.

"A Murder Is Announced" was adapted for the stage from a 1950 mystery with Miss Jane Marple as the Christie amateur sleuth. Dame Agatha once confided that she always preferred Miss Marple, the spinster busybody, to her more famous Hercule Poirot, the prim, pompous dandy of a detective.

As Miss Marple, Pauline Flanagan, wearing substantial shoes and tweed suit, gossips, fusses, and irritates the police as she carries on her own detection. Flanagan is a trifle too sturdy for the Miss Marple of the Christie mysteries. In the books, she is a tall, spare woman who becomes more fragile in her later appearances. But, then, Margaret Rutherford, the Miss Marple of the movies, did not fit the Christie mold either.

Whatever the physical discrepancies, Flanagan bustles about as a likable busybody in what turns out to be a supporting role for Miss Marple.

For "A Murder Is Announced," Dame Agatha has assembled a lively assortment of English characters in the village of Chipping Cleghorn, where Miss Marple has come to take treatments for rheumatism at the local spa.

There is Letitia Blacklock, former secretary to a deceased millionaire; her old, slightly senile friend, Dora Bunner; two young second cousins who call her Aunt Letty, a young woman befriended by Lettia, and a neighbor with a son who aspires to be a writer.

The murder is announced in an advertisement in the local newspaper. And, sure enough, as the clock strikes 6:30 p.m. on a Friday the 13th, the lights go out. Shrieks and shots follow. When the lights go on, a body lies center stage.

Only a cad would reveal any more of the plot.

As Dora, Ruby Holbrook is just splendid as the muddled friend who drops clues from the past and knows how to milk a headache for sympathy. Her expression droops with her shoulders when she is disappointed. In the other leading roles, June Hansen and James Secrest carried off the roles, of Letitia and Inspector Craddock with stylish performances. With one glance to the heavens, Secrest can convey the feelings of the long-suffering police inspector who must try to ferret information from the reticent witnesses.

The rest of the cast adds to the polished production fashioned under the able direction of Leo Brady, who approached the Christie play with goodhearted affection and respect. Ilona Dulaski is explosive as the Slavic maid, and Catherine Flye, Michael Rothhaar, Cecelia Riddett and Anthony Risoli make an engaging quartet of young people with mysterious pasts.

And Rudi Scherz is a fine corpse.

"A Murder Is Announced'" ends its three-week run at Olney on June 22.