Investors in Time Warner Inc., whose shares touched a two-year low in mid-July, are seeking signs of a turnaround on August 2, when the world’s largest media company is set to introduce its fourth plan in five years to save its online unit AOL.

AOL is widely expected to announce that it will give its e-mail and Web services away for free, hoping to win back customers who had switched to other free services from rivals like Google Inc. and Yahoo Inc. (Nasdaq:YHOO - news).

The new strategy, which will be discussed at a Time Warner board meeting in New York on Thursday aims to boost online advertising sales, but analysts say it is a risky move as its subscription business currently accounts for 80 percent of AOL’s revenue.

AOL is still expected to continue to charge for dial-up Internet access, but it will no longer advertise the service.