UPDATE 1-Sirius in talks to buy Canada's AusPotash

* Says may issue up to 115.5 mln shares

* Says AusPotash will add C$2.9 mln to its cash resources

* Shares rise 5.2 pct (Adds details)

Sept 15 (Reuters) - Sirius Exploration Plc (SXX.L), a mining and exploration holding company mainly focused on North America and Australia, said on Tuesday it was continuing talks to acquire private Canadian firm AusPotash Corp through an issue of up to 115.5 million shares.

AusPotash has acquired an interest in two potash exploration permits in a region of Queensland, Australia, recognised for its salt and potash deposits.

Exercise of warrants and options will provide Sirius with C$2 million ($1.85 million) as aresult of the acquisition, it said.

Sirius said AusPotash will add a total of C$2.9 million to the company's cash resources, if all the options are exercised before the acquisition.

Sirius shares, which hit a 52-week high of 15.75 on Sept. 11, were up 5.2 percent at 15.25 pence at 0757 GMT on the London Stock Exchange.

($1=1.083 Canadian Dollar) (Reporting by Balachander Surianarayanan in Bangalore; Editing by Jarshad Kakkrakandy)