Synopsys Inc. is in advanced talks to acquire engineering software provider Ansys Inc. for about $35 billion, people with knowledge of the matter said.

Synopsys is discussing paying about $400 a share for Ansys, in a deal that could be announced as soon as next week, according to the people, who asked to not be identified because the details aren’t public. A final agreement hasn’t been reached and talks could still fall through or the terms could change, the people added.