Before passing over the call to Paolo for his opening remarks, I would like to briefly comment our quarterly results. During first quarter of 2012, sales increased 13% to $2.6 billion compared to $2.3 billion recorded in the first quarter of last year. However as anticipated last quarter they decreased 5% sequentially as sales were impacted by lower pipe shipments or HPI and pipe line in addition to lower OCTG shipments in Columbia and Saudi Arabia. Our EBITDA for the quarter reached 700 million, which was 26% higher than the corresponding quarter of 2011 and 2% higher sequentially.
Our EBITDA margin continued to improve reaching 27% due to lower raw material cost and plant our location efficient. Average selling prices in our Tubes operating segments were up 8% compared to the corresponding quarter of last, but flat sequentially.
During the quarter, our sales of high-end seamless products remained stable at 54% of our total seamless volume, but are expected to be higher during the coming quarters of the year. During the quarter, cash provided by our operating activities was over 600 million allowing our net cash position to decrease by just 65 million to almost 160 million after investing more than 500 million in (inaudible) and almost 200 million in capital spend.
Now, I will ask Paolo to say a few words before we open the call to questions.Paolo Rocca Thank you, very much Giovanni, and good morning to all of you. This quarter also our sales in shipment came in lower sequentially. We were able to increase our operating income and margin. Thanks to a more efficient cost performance. In the coming quarter we are confident that we can maintain these levels of operating margin on a higher level of sales. Our sales in North America rose 10% sequentially during the quarter and accounted for 56% of our two operating segments sales, and 52% of our total sales. We are being improving our performance in North America at all levels. This quarter our heat man Mill in Kansas produced a record level of heat treated product our McCarty premium facility in Houston spread a record level of premium joint. And our raw materials business in Canada produced a record level of seamless product. This production record was by substantial reduction in the injury frequency rate in our U.S. mills and reflected the investment we have made in the plants.