DENVER (AP) ¿ Shares of Alpha Natural Resources Inc. rose Friday after an analyst upgraded his rating on the coal producer because of its plan to purchase Foundation Coal Holdings Inc. for $1.4 billion in stock. In a research note, Goldman Sachs analyst Brian Singer also raised a target price for both Arch Natural and Foundation Coal and maintained Foundation's "Buy" rating. The acquisition, if completed, would give Alpha Natural more diversified assets, improve growth opportunities and be accretive to cash-on-cash returns of both companies, Singer said. He rated Alpha Natural a "CL-Buy," up from "Neutral," and raised his six-month multiples-based target price to $38 a share from $32 a share. Singer revised his earnings per share estimates for Alpha to 57 cents from 60 cents in the second quarter of 2009; 76 cents from 75 cents in the third quarter and 72 cents from 70 cents in the fourth quarter. For the full year, he estimated earnings per share of $2.71 which is unchanged. Foundation's six-month multiples-based target price was raised to $41 from $33 to reflect additional earnings based on its recent settlement of a contract dispute, Singer said.