Stratasys Ltd.'s board of directors unanimously rejected a second takeover bid from Nano Dimension, fewer than two weeks since rebuffing the Israeli company's initial offer.

Nano Dimension's revised bid, made last week, increased its offer to $19.55 a share, up from $18. Stratasys — which makes polymer-based 3D printers and operates out of Eden Prairie and Rehovot, Israel — decline that offer Monday, as it did the first one.

Stratasys received the original unsolicited bid in early March. Analysts who follow Stratasys and the 3-D printing industry said the bid undervalued the company, and the board of directors unanimously rejected the deal, valued at $1.2 billion.

Analysts didn't like Nano's revised offer much better.

"We reiterate that accepting the current acquisition offer from Nano Dimension is not in the best interest of SSYS or its shareholder," wrote Janice Quek, an analyst with CFRA Research.

Stratasys itself seemed to agree.

"The Stratasys board and management team are confident that Stratasys' standalone plan will create significantly greater value for its shareholders than the Nano proposal," said the company about the second rejection.

Stratasys' stock finished Monday at $16.38 a share, down 0.9%. Nano Dimension's stock was at $2.98 a share, unchanged on the day.

Nano Dimension is Stratasys' largest shareholder. Nano is a much smaller company than Stratasys with annual revenue of $43.6 million to Stratasys' $651.5 million.

J.P. Morgan is serving as Stratasys' financial advisor.