1.   He emphasized, however, that the wider spread for Nasdaq stocks did not necessarily prove that market makers on the exchange had colluded to keep them wide.

2.   Large Nasdaq dealers are under Justice Department investigation to determine if they colluded to keep trading spreads unusually wide.

3.   Such a set fee could only hold if the firms colluded to keep the price at that level, the complaint maintains.

4.   The Justice Department conducted a two-year investigation into whether Nasdaq market makers colluded to keep spreads on stocks unnaturally wide.

5.   The Justice Department launched an investigation a year ago of whether market makers on the computerized Nasdaq market collude to keep profits artificially high at the expense of customers.

6.   The Justice Department is also investigating whether dealers on Nasdaq colluded to keep trading spreads unusually wide.

7.   The lack of so-called odd-eighths quotes suggested to the professors that brokers were colluding to keep spreads high.

8.   The plaintiffs accuse the firms of colluding to keep spreads -- the difference between the prices at which stocks are bought and sold -- artificially wide.

9.   The SEC and the justice department concluded that Nasdaq market makers had colluded to keep spreads wide and profits high.

10.   The suits allege the companies colluded to keep a low-cost version of tamoxifen off the market.