“TENDER IS THE NIGHT,” Sunday, 8-10 p.m....

“TENDER IS THE NIGHT,” Sunday, 8-10 p.m. Showtime (Cable)--The last TV miniseries to depict the “lost generation” of American expatriates in Europe after World War I was last December’s twisted version of Ernest Hemingway’s “The Sun Also Rises” on NBC.

The results are infinitely sunnier for Showtime’s first miniseries, a swell six-hour rendering of F. Scott Fitzgerald’s “Tender Is the Night.” Part I airs Sunday, with subsequent one-hour episodes to be shown Tuesdays at 10 p.m. in November.

Yet this is hardly a sunny story. The romance and emptiness are here, reflecting Fitzgerald’s favorite themes: wealth and moral corruption.

“Tender Is the Night” is about the destructive marriage of a brilliant psychiatrist and a wealthy schizophrenic woman. Their relationship is played out against the lush, fast-lane ambiance of the French Riviera in the 1920s.

Dick Diver (Peter Strauss) and Nicole Warren (Mary Steenburgen) meet and fall in love while she is a deeply troubled and dependent patient at a Swiss psychiatric clinic. Yet the woman he pledges himself to for “now and tomorrow, next week, always” will literally drain his life force.

It’s no coincidence that Fitzgerald has given his flawed hero the name of Diver. During their marriage, Nicole will blossom while Dick sinks lower and lower into drink and disillusionment.

“Tender Is the Night” is somewhat autobiographical, for Fitzgerald’s own talent often faded during a storied relationship with his erratic, mentally ill, oft-institutionalized wife, Zelda.

His nomadic flappers here are essentially weak, miserable and indulgent Americans for whom fun is an end in itself. An English production crew has adeptly captured their tone for American TV.

This is a BBC production in association with Showtime. Jonathan Powell (“Tinker, Tailor, Soldier, Spy”) was the executive producer, Robert Knights the director and Dennis Potter the writer.

They succeed despite the miscasting of Steenburgen in the critical role of Nicole. Somehow she hasn’t the mystery, the allure, the oomph.

Peter Strauss, though, is the soul of this production, utterly convincing as the plummeting Diver. His eyes seem to grow emptier and emptier as the flame in him diminishes until it is out.

Meanwhile, John Heard is outstanding as the drunken cynic Abe North and Sean Young does nicely as Rosemary Hoyt, the teen starlet who has a lengthy fling with Dick.

All in all, a maxi start for Showtime’s first miniseries.