PIERRE (AP) - The South Dakota Supreme Court has upheld the constitutionality of the state tax on insurance premiums.

Metropolitan Life Insurance Co. had argued that South Dakota's tax violated the federal and state constitutions because it treats companies organized under South Dakota law differently than it treats those based in other states.

The tax rate is the same for all insurance companies, but companies get tax reductions for locating main or regional offices in South Dakota.

The Supreme Court says the tax structure is constitutional because the tax rate depends on each company's decisions regarding office locations.