Offshore products generated revenues and EBITDA of $237.3 million and $40.4 million in the fourth quarter of 2012 compared to revenues and EBITDA of $186.1 million and $37.5 million, respectively, in the fourth quarter of 2011. Revenues and EBITDA increased 27% and 8% year-over-year, respectively, primarily due to a revenue mix favoring our connector products and production equipment coupled with contributions from Piper Valves which was acquired in July 2012. Our EBITDA margin percentage decreased to 17% in the fourth quarter of 2012 compared to 20% in the fourth quarter of 2011 largely due to a mix of revenues which included greater conductor casing sales year-over-year coupled with negative inventory adjustments totaling $2.5 million. Backlog totaled $561 million at December 31, 2012 compared to $597 million reported at September 30, 2012 and $535 million reported at December 31, 2011. Major backlog additions during the quarter included connector product orders, production equipment and deck equipment orders.
Tubular services generated revenues of $455.3 million and EBITDA of $19.0 million during the fourth quarter of 2012 compared to revenues and EBITDA of $386.0 million and $17.3 million, respectively, in the fourth quarter of 2011. Revenues improved 18% and EBITDA increased 10% year-over-year primarily due to the 13% year-over-year increase in the Company's OCTG shipments resulting from increased activity in the Gulf of Mexico coupled with certain market share gains onshore. Gross margin as a percent of revenues were 5.1% in the fourth quarter of 2012 down from the 5.6% margin reported in the fourth quarter of 2011 primarily due to lower margin sales into certain onshore markets as a result of declining OCTG prices throughout 2012. The Company ended the quarter with $450.2 million of OCTG inventories, down $73.5 million, or 14%, from September 30, 2012. The decrease in inventories was primarily due to deepwater Gulf of Mexico shipments made during the fourth quarter of 2012.