Capitol Hilt's ASTA Theather is risking a revival of Noel Coward's "Private Lives," and to both their credits it remains a winning play. What a deft, vibrant piece this is, written 47 years ago. Those for whom playwriting began in this decade will learn how much can be done through lean dialogue.

It look the British novelist Arnold Bennett, to find in this play - which critics of 1930 called "thin" or "tenuous" - "the Congreve of our day." While the situation and manners remain of the period, the characters are timeless and individual. Two newly married couples - Sybil and Elyot, Amanda and Victor - occupy adjacent terraces in a hotel overlooking the Mediterranean. Five years earlier Amanda had divorced Elyot and so astonished to see each other are they that . . .

Apart from the defined characterizations within the witty, literate lines, the comedy's adroitness lies in the balance of the couples. Elyot and Amanda are the central figures to be sure, but because Coward wrote them for Gertrude Lawrence and himself does not mean that he neglected the other two roles, acted at the American premiere by the unknown Laurence Olivier and his first wife, Jill Esmond.

In his staging Russell J. Toscano recognizes that Sybil and Victor are not to be sloughed off. While his players are not to complete professional command, none is in the amateur class.

Karen Bayly's Amanda and Stuart Lerch's Elyot are well paired with Patricia Turney's Sybil and Marc Adams' Victor. Young Ruth Moss does right by the clumsy servant and, some words apart, I did not find the effort for British English, as painful as usual.

This is the third bill at Dona Cooper's new theater at 507 8th St. SE, and by far the best. Performances are Wednesdays through Sunday at 8 p.m.