* Australian Throsby had overseen raft of senior hirings
* Move comes amid activist pressure to trim investment bank
* Barclays says departure not linked to that pressure (Adds details, context)
LONDON, March 27 (Reuters) - Barclays announced on Wednesday the surprise departure of its investment banking head Tim Throsby as part of wider leadership changes, adding the moves were not linked to pressure from an activist investor to shrink its investment bank.
The departure of the Australian will see Chief Executive Jes Staley assume more direct control of three investment banking divisions, banking, markets and corporate bank, that had previously reported to Throsby.
"I am making some leadership changes to ensure a much stronger and closer focus on the two respective hemispheres of our diversified Group - our Consumer and Wholesale businesses," Staley said.
The move comes amid a battle between Staley and activist investor Edward Bramson, who is seeking a seat on the bank's board to try and force it to shrink the underperforming investment bank that Staley has championed.
Asked whether Throsby's departure was linked to the pressure from Bramson's Sherborne investment vehicle, which holds a 5.5 percent stake in Barclays, a spokesman for the bank said: "It is not linked in any way, if Sherborne were not on our investor register we would still have made these changes."
Barclays hired Throsby, who like Staley came from JPMorgan , in September 2016 after a six-month search for the vital job overseeing the bank's trading and advisory businesses.
In the following years, Throsby oversaw a raft of senior hirings as Barclays struggled to improve returns at the unit, which have consistently lagged its more profitable retail banking and credit card businesses. (Reporting by Lawrence white in London and Noor Zainab Hussain in Bengaluru; Editing by Bernard Orr and Mark Potter)