SINGAPORE, June 15 (Reuters) - Software firm MicroStrategy said it has not received a margin call against its bitcoin-backed borrowing on Wednesday, and it has plenty of extra collateral to pledge if necessary.

MicroStrategy borrowed $205 million from crypto bank Silvergate Capital in March, mostly secured against bitcoin. On Tuesday bitcoin's price briefly dropped below a level company officers had said could trigger extra capital requirements.

"MicroStrategy has not received a 'margin call' against our Silvergate loan even as bitcoin prices have fluctuated recently," the company said in an emailed statement.

"We can always contribute additional bitcoins to maintain the required loan-to-value ratio ... even at current prices, we continue to maintain more than sufficient additional unpledged bitcoins to meet our requirements under the loan agreement." (Reporting by Tom Westbrook; Editing by Jacqueline Wong)