Senior SA Liberal to retire within a year

Former Liberal leader Iain Evans will quit the South Australian parliament within 12 months, which will spark a by-election.

The opposition treasury spokesman made the announcement on Friday after meeting state Liberal leader Steven Marshall.

He said he would not seek a shadow cabinet position in Mr Marshall's coming reshuffle.

"After 21 years representing the electorate of Davenport and my 46-year involvement in politics, I have made the decision to leave the SA parliament in the next 12 months and seek a new career in the private sector," he said.

Mr Evans, 55, has served as a minister, as SA Liberal leader and as deputy leader.

His announcement comes less than two weeks after former fellow frontbencher Martin Hamilton-Smith defected to become a minister in the minority Labor government.

Ten other MPS are on the Liberal front bench.