(Reuters) -Australia's Bigtincan Holdings Ltd completed a A$35 million ($23.54 million) equity raising on Thursday, hours after top shareholder and suitor SQN Investors called it "highly dilutive" and "value-destructive".

SQN, Bigtincan's top shareholder with a 13.6% stake, had voiced its opposition to the placement, urging the software firm to not go through with any capital raise or acquisitions, in a letter released in early market hours.

"We urge you to not pursue any capital raise or do any acquisitions at this time," SQN said in its letter to Bigtincan, referring to a media report that the Sydney-based company's shares were on a trading halt pending a placement.

"We would urge you to instead honour your fiduciary obligations and engage with the various parties that have approached you about a control transaction, including SQN Investors."

After market hours, Bigtincan said it had concluded a placement resulting in the issue of 50 million new shares and a share purchase plan leading to an issuance of up to A$10,000 worth of new shares to execute various mergers and acquisitions.

The issue price of A$0.60 per share represented a sharp discount to SQN's buyout offer of A$0.80 apiece made last week, which valued the Sydney-based software firm at A$441.9 million.

"The company has identified a number of potential strategic M&A targets that it would like to pursue to accelerate its product roadmap," Bigtincan said in its statement.

SQN did not immediately respond to a Reuters request for comment on the capital raising.

($1 = 1.4865 Australian dollars)

(Reporting by Roushni Nair in Bengaluru; Editing by Christian Schmollinger and Subhranshu Sahu)