JERUSALEM, Oct 2 (Reuters) - Israeli software maker Formula Systems said on Wednesday it signed a definitive stock purchase agreement with its unit, Matrix IT Ltd, in which Formula will sell shares in other subsidiaries to Matrix (Tel Aviv:MTRX.TA - News).

Formula said the transaction will "create the largest information technology company in Israel, providing Matrix customers with critical mass, operating effi`ciencies and a more unified corporate structure and identity".

The company said in a statement it will sell ordinary shares in its units New Applicom (Tel Aviv:APLI.TA - News), Sintec Advanced Technologies (Tel Aviv:SYTC.TA - News) and Sivan Training and Systems (Tel Aviv:SVAN.TA - News) to Matrix for about 129 million shekels ($27 million).

The closing of the sale is subject to the approval of Matrix's shareholders. Matrix is an IT integrator and IT solutions and services provider.

Formula, which owns 85.5 percent of Matrix, also said it will commence a cash tender offer for the ordinary shares of New Applicom, Sintec and Sivan that Formula does not already own.

Participating shareholders will receive 17.5 shekels for each new share of New Applicom, four shekels for Sintec shares and 0.7 shekel for each Sivan share.

Matrix has informed Formula that after the completion of its purchase of Formula's interest in New Applicom, Sintec and Sivan, Matrix will hold an exchange offer for all shares in the three companies not sold to it by Formula.

The companies anticipate that participating shareholders will receive three ordinary shares of Matrix for each share of New Applicom tendered, 0.65 shekel of Matrix for each Sintec share and 0.2 a share of Matrix for each Sivan share.

Formula said the transactions will "further Formula's goals of simplifying and enhancing the efficiency of our corporate structure and strengthen Formula's focus on its principal operating divisions."

Formula's shares were up 0.7 percent at 44.20 shekels at midsession in Tel Aviv. Matrix was down 1.4 percent to 7.10 shekels, while Sintec was down 0.3 percent down at 3.99 shekels and Sivan's shares were up 46 percent to 0.99 shekel.