The Minnesota Department of Commerce plans to fine a gas station chain for repeatedly selling gas below the state's legalminimum price. The agency says it's fining Midwest Oil $140,000 for breaking a state formula based on wholesale prices, fees and taxes to determine a daily floor for gas prices. Minnesota's price law was intended to prevent large oil companies from driving smaller competitors out of business -- but some critics argue it fails to protect consumers. The Commerce Department says Midwest-owned stations in Anoka, Oakdale and Albert Lea sold gas below the minimum price on 293 days in 2005. Midwest officials couldn't be reached for comment.