Nasdaq OMX GroupNasdaq OMX Group ( NDAQ) is no stranger to the M&A market. After NYSE Euronext ( NYX) and Deutsche Boerse agreed to a February $9 billion tie-up, Nasdaq and IntercontinentalExchange ( ICE) teamed up on a richer $11.3 billion April bid for NYSE Euronext. That bid was quashed by the Department of Justice in May. Not so much an acquirer, Morningstar now highlights Nasdaq OMX as a "as an appealing target by a larger exchange operator, perhaps from outside the U.S." The benefit may be Nasdaq's $4 billion market cap and diversification among different geographies and financial products like stocks, futures, options and index derivatives, according to Morningstar The New York-based exchange operator operates the Nasdaq stock market, in addition to the Boston and Philadelphia Stock Exchanges and other U.S. options, cash equities future and derivatives clearing businesses. After a 2007 merger with OMX for $3.7 billion, Nasdaq took control of seven exchanges in Nordic countries like Sweden, Denmark and Finland, among others. Morningstar gives Nasdaq OMX Group a four star rating and a fair value of $33 a share, an over 30% premium to current share prices of $25.32. The company is expected to earn $62 cents a share in its first quarter 2012 results due in February, according to Zacks consensus estimates. Analysts give Nasdaq OMX Group an estimated price target of $29.53 a share on 2012 revenue of $3.5 billion and profit of $488 million, according to data compiled by Bloomberg. For more on Nasdaq OMX shares, see 4 stocks for volatile markets . For more on exchanges M&A see why the MF Global failure won't alter exchange evolution. While Morningstar doesn't specify a takeover candidate for Nasdaq, previously announced bids may indicate what can and can't work as a deal. Currently, the NYSE Euronext and Deutsche Boerse tie-up is on jagged rocks with European competition authorities, while a February merger attempt between the London Stock Exchange and the Toronto Stock Exchange was iced. Both the LSE and TSX have since found new tie-ups. Depending on the NYSE merger, Deutsche Boerse may have an easier time looking at other U.S. exchanges, with less of a presence in European derivatives than NYSE Euronext. Morningstar also highlights the CBOE ( CBOE) as being an "easily digestible" target of a U.S. exchange because of its small size and lack of product diversification.