Software maker Medidata Solutions Inc has rescheduled its initial public offering until next week, one of the deal's underwriters said Monday, setting the stage for the busiest week for IPOs since April 2008.

Medidata, which serves drugmakers such as Johnson & Johnson and seeks to raise about $75.6 million, plans to price its IPO on June 24, with trading to start the following day.

Two other IPOs, by Chinese water treatment equipment distributor Duoyuan Global Water Inc, and Chemspec International Inc, a Chinese chemicals company, are set to price next week as well.

If all three deals go ahead as planned, it will be the busiest week for IPOs in the United States since the week of April 21, 2008, which saw four deals, including billion-dollar IPO by Intrepid Potash Inc and American Water Works Co Inc.

So far in 2009, seven IPOs have launched -- excluding those by real estate investment trusts -- with dollar proceeds down about 94 percent over where they were at this time last year, according to Thomson Reuters data.

Medidata's IPO was initially going to price on June 17.

(Reporting by Phil Wahba, editing by Maureen Bavdek)