MADRID, Jan 12 (Reuters) - Spain’s High Court on Tuesday increased the pressure on two former managers of troubled engineering and energy firm Abengoa, giving them 24 hours to deposit millions of euros in bonds as it investigates mismanagement allegations.

The court is looking into compensation payments handed out to two ex-bosses at Abengoa, which is racing to reach a deal with its creditors to avoid becoming Spain’s biggest ever bankruptcy.

In December the High Court demanded a bond of 11.5 million euros ($12.5 million) from former Chairman Felipe Benjumea and 4.5 million euros from ex-Chief Executive Manuel Sanchez to cover potential liabilities, after a complaint by some Abengoa bondholders over the firm’s severance payouts.

On Tuesday the High Court said in a written ruling that insurance contracts presented by the former managers to cover the funds would not adequately cover all eventualities, adding that the two would have to provide the cash themselves.

The court is investigating whether there are grounds to charge Benjumea and Sanchez with mismanagement, and it is also looking into insider trading accusations against Sanchez.

Magistrates had previously said they could freeze Benjumea and Sanchez’s assets if the bonds were not posted.

Reuters could not immediately reach Benjumea or Sanchez for comment.

Abengoa, which received extra funds from banks last month to keep operations ticking over, is hoping to reach a deal with its creditors before a March 28 deadline, after which it would have to file for insolvency. ($1 = 0.9212 euros) (Reporting by Sarah White; Editing by Angus Berwick and Keith Weir)