WASHINGTON — MasterCard has asked the U.S. Supreme Court to review a lower court's decision that would force the two card associations to open up the network of banks and credit unions that issue their cards to card brands like American Express and Discover. In a previous decision, the U.S. Second Circuit Court of Appeals had ruled that VISA and MasterCard competed too much to be considered monopolies among themselves, but ruled against the card brand's requirement that limited issuers' ability to issue other brands of cards. "We are asking the Supreme Court to review the decision, because it sets a precedent that casts doubt on the operations of many existing joint ventures, not just the MasterCard joint venture," said MasterCard general counsel Noah J. Hanft. "Joint ventures bring efficiencies and often create innovations that are not possible by a single firm. If a decision finding antitrust liability for joint ventures without proof of harm to competition is allowed to stand, it exposes many businesses that are structured as joint ventures to new and unjustified legal risks. That's why we're hopeful that the Supreme Court will recognize the importance of the issues and review the case," said Hanft.