President Bush notified Congress late Friday that he was putting off a decision on whether to shift $350 million in previously allocated funds from the MX missile into testing for the Midgetman.

Last year, Congress effectively passed the delicate decision to the new administration by giving the Midgetman $250 million and the rail-based MX $600 million but with the proviso that no more than $250 million could be spent on the MX by Feb. 15.At that time, if Bush wanted to reallocate the extra $350 million in MX money, he was to notify the Congress.

"Until April 3, 1989, I anticipate obligating no more than $250 million of the $600 million appropriated for the fiscal year 1989 MX Rail Garrison program," Bush said in a letter signed Friday after noon before he departed for Camp David, Md., and sent to the chairmen of the armed services and appropriations committees in the House and Senate.

Bush, in announcing the delay, said the question will be part of his sweeping review of national security strategy.

"The modernization of our land-based strategic forces has raised a number of issues that will necessitate consultation with you and other members of Congress before any final proposals are made on this critically important matter," he said.

Utah's Hercules Aerospace and Morton Thiokol both have stakes in MX production, and Hercules also is involved with Midgetman production.

Bush has yet to give formal notice of his spending priorities in the Defense Department. His $1.16 trillion budget proposal for fiscal 1990, submitted last Thursday, froze defense spending for a year but lacked any guidance on which areas or programs would be cut to achieve that level.

His proposal did not present any indication on how he would move on the MX vs. Midgetman issue.

Fifty MX missiles now are based in silos at Air Force bases in the West.

The single-warhead Midgetman still is under development and is far more expensive.