Rockwell’s Planned Purchase of Avionics Company Collapses : Acquisition: Neither party will say why the $200-million deal for a unit of Sundstrand Corp. failed in the final stages.

SEAL BEACH — Plans by Rockwell International Corp. to bolster its civilian aviation controls division with the acquisition of Sundstrand Corp.’s $200-million avionics unit were dashed Monday as the two companies failed to reach final agreement on the deal.

Neither side would say whether the hang-up involved disagreement over numbers, such as Sundstrand Data Control’s market value, or other factors like government approval of the merger or Rockwell’s plans for the Sundstrand division’s 1,500 employees.

Sundstrand agreed several months ago to sell its data control unit to Rockwell for $225 million. The unit, which manufactures flight management systems and data recorders--the so-called “black boxes” used in aircraft cockpits--had 1991 sales of $216 million.

A Rockwell spokesman said Monday that the Sundstrand Data Control facilities in Washington and Arizona would have become part of Rockwell’s Collins Commercial Avionics division, which is in Cedar Rapids, Iowa. Rockwell had fiscal 1992 sales of $10.6 billion.

Officials of Sundstrand, which has its corporate headquarters in Rockford, Ill., said they would continue pursuing options including sale of the division.

Analysts had said that acquisition of Sundstrand Data Control would have strengthened Rockwell’s commercial product lines--a key growth area for the company in this era of declining defense spending.