Diesel engine maker Cummins Inc. posted its most profitable fourth quarter in company history, thanks to a rush on engines that won't have to conform to new emission standards that took effect this year.

Cummins said year-over-year sales grew 3 percent from $3.29 billion in the fourth quarter of 2008 to $3.4 billion in the same period last year. Net income attributable to Cummins increased from $43 million, or 22 cents a share, to $270 million, or $1.36 per share. The net income attributable to Cummins does not include earnings from various joint ventures.

New emissions standards for diesel engines drove fourth-quarter sales, company spokesman Mark Land said. Many customers rushed to buy under the old standards, because engines were cheaper and more familiar. "Our revenues were significantly higher because of that," Land said.

Full-year revenue was $10.8 billion, down 25 percent from $14.3 billion in 2008. The company noted that despite a deep global recession, its results improved from quarter to quarter throughout 2009.

CEO Tim Solso said that through early cost reductions, the company delivered as promised in 2009. "We earned a solid profit during the deepest recession in decades and generated a significant amount of cash while continuing to invest in technologies and programs critical to our success," Solso said.

Shares of Cummins rose close to 9 percent on Tuesday by the end of trading, finally resting at $51.12.