I think I read this in a magazine back in the 1970s or perhaps 1980s. As I recall, the plot went like this:
The protagonist is working in a morgue when a body is brought in. The dead man was a jet-setter who was killed suddenly--hit by a bus, or something fell on him. While processing the body, the protagonist finds a ring on the body's finger and decides to keep it. Shortly afterwards, some jet-set friends of the dead man show up looking for the ring, but the protagonist feigns ignorance and the friends eventually leave.
The man discovers that squeezing the ring lets him relive the previous minute of his life, and he can live that minute differently. As I recall, he uses the ring to seduce a woman by saying and doing just the right thingsrefining his technique until it works, so to speak. Later, he uses the ring to win big at a casino. Soon the man is on his way to being a member of the jet set himself.
Finally he's on a plane, flying to Europe or some place. There's an in-flight emergency and the plane breaks up in mid-air. The man finds himself doomed to keep squeezing the ring, as I think the last line goes, "because the alternative was to fall into the waiting sea".
The Futurama series finale uses the same time-travel mechanism and even the same eventual predicament. ButI thought the Futurama story might be based on the story I'm looking for, but I haven't found any references to the old story on any Futurama pages.