Medco still needs to assemble a funding package to pay for the deal if successful, and has also insisted on similar break-free conditions Novus has in place with Sunov, led by Novus CEO Bob Williams.

Medco is also seeking a recommendation from the independent Novus directors that shareholders accept the offer in the absence of a superior offer. It had previously offered $1.70 per share. Sunov had offered $1.85.

Medco also said it would provide further details to Novus shareholders in relation to the new offer no later than 31 May.