The bidding war for business software group Retek heated up Friday as Oracle boosted its bid over the offer of German-based SAP. Oracle's offer announced late Thursday was for $11.25 (8.47 euros) a share, valuing the company at around $630 million. The California group was seeking to trump the offer made this week by SAP of $11 a share. Analysts say Oracle, the world's second largest software group, is anxious to block a move by SAP, the leader in business management software, to get a stronger foothold in the US market. Oracle chief executive Larry Ellison said in the statement, "Our North American applications business is larger than SAP's. We intend to defend our number one position." Oracle also said in a statement it has already purchased 5.5 million shares of Retek common stock, representing nearly 10 percent of shares outstanding. SAP had no immediate comment on the Oracle bid.