PP and share buybackThey were in a buyback period when they made the PP - the recent announcement is simply a continuation of the buyback plan.
If you compare the average price of their share buybacks to that of the PP, what TOT is doing makes sense. They've bought back shares for less than they received on the issuance of new shares. Also, by cancelling the shares bought back, they reduce the dilutive effect of a new offering, making the latter more attractive to an underwriting syndicate and more acceptable to existing shareholders.
If they simply cancelled the buyback and issued more shares in a sccondary offering to the market, they risk a sell off and consequent share price decline - at least that would be the likely short-term effect. A simultaneous PP and buyback strategy hedges against that risk.
Other companies have done the same - e.g. Transalta last year I think.
Anyway, I'm no expert on this - I'm just putting 2 and 2 together and getting 5!
Just my take on it.