Myers Industries Inc., a plastic parts supplier to the RV industry, reported lower earnings despite higher sales revenue during the fourth quarter and the full year 2000.

The company, which bought RV industry supplier Best Plastics Inc. of Cassopolis, Mich., last year, earned $4.5 million during the fourth quarter, a 54% decline from the same period a year earlier.

Myers’ full year 2000 earnings were down 23% to $24 million.

The company’s fourth quarter sales increased 3% to $171.3 million and its full year 2000 sales were up 12% to $652.7 million.

Myers’ earnings declined because of expenses related to the closing of a plant in Dayton, Ohio, the fact the cost of resin, particularly for high-density polyethylene, was 50% higher in 2000 that it was in 1999, and the impact of the slowing auto market.

Without the purchase of Best and other acquisitions during 2000, Myers’ sales revenue would have been up only 1% higher during the fourth quarter and up only 3% for the full year 2000.