Gas prices in Massachusettes were on the decilne for a consecutive six weeks. Four cents under the national average Massachusetts gas prices were on a consistent decline until prices recently spiked in the last few weeks. Three weeks ago when pices began to rise again. According to a survey by AAA Southern New England, gas prices have risen three cents from last week to an averaged $2.63 pergallon of regular unleaded. Still six cents under the national average of $2.69 per gallon, prices are expected to keep rising as the holiday season appraoches.