SYDNEY, April 21 (Reuters) - Australian Clinical Labs (ACL), a pathology provider owned by domestic private equity firm Crescent Capital Partners, is seeking to raise $315 million in an initial public offering next week, according to a memo seen by Reuters.

The company and its advisors, Merrill Lynch Equities and Goldman Sachs, will offer shares at A$4 each at an institutional bookbuild on April 27, valuing the company at A$809 million, according to the memorandum sent to investors.

A listing of ACL, one of the three big pathology companies in Australia servicing more than 90 private and public hospitals, would be Australia's largest IPO of the year, adding to the already four-fold increase in public offerings in the first quarter.

Last month, KKR's, Värde Partners and Deutsche Bank raised A$200 million in exchange for 7.7% of its consumer lender Latitude Financial, selling shares at a price 13% below what Japan's Shinsei Bank paid for Latitude shares weeks before.

ACL, which according to the Australian Financial Review sought buyers for a private sale last year, expects to file a prospectus with the corporate regulator by April 28, open the shares offer to retail investors on May 6, and debut on the exchange on May 14, the memo said.

($1 = 1.2957 Australian dollars) (Reporting by Paulina Duran in Sydney; Editing by Louise Heavens)