Emerson Electric said on Monday that its $265 per-share offer to acquire Aspen Technology was its "best and final" price. The announcement comes days after activist investor Elliott Management said it invested over $1.

Emerson Electric's $265 per share tender offer for Aspen Technology is labeled as its best and final price despite criticism from Elliott

With a more than $1.5 billion Emerson holding, Elliott has claimed that the $265-per-share offer undervalues Aspen Tech and is advocating a larger proposal. Mark Schappel, a Loop Capital analyst, said Elliott is probably going to persuade enough minority investors Aspen Tech is worth far more than Emerson's current offer.

Elliott Investment Management has emerged as the largest minority investor in industrial-software company Aspen Technology Inc., with a position worth more than $1.5 billion, people with knowledge of the matter said.