As the House began work on a $183 billion defense authorization bill yesterday, President Reagan launched a preemptive strike by making public letters urging Congress to restore funds for production of the MX missile and military cargo planes.

The president's letters to House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) appeared to have a dual objective, according to congressional sources.

One is to avert acceptance of amendments to be offered in the House to take even more money out of the controversial MX program.

The other is to set up a situation in which an eventual House-Senate conference to compromise differences on the fiscal 1983 defense bill would lead to restoration of funds for MX and the expanded fleet of C5 cargo jets sought by the Pentagon.

The MX is supposed to become the land-based component of the triad of intercontinental-range U.S. nuclear striking power, which also includes missile-firing submarines and bombers.

But the Senate Armed Services Committee, annoyed at the Pentagon's inability to figure out exactly where and how to base MX, has cut the $1.5 billion in procurement funds this year for the first batch of nine missiles plus spares.

The committee has also demanded that the Pentagon decide on a permanent home for MX by Dec. 1 before the funds will be restored.

House committees have cut about $500 million from MX but have left production funds in the budget. Amendments are expected, however, to cut all such funds.

In his letter, Reagan said, "I cannot overemphasize to you the serious negative impact" that cutting out MX production "can have on our negotiations with the Soviets" in the strategic arms reduction talks (START) under way in Geneva and on the overall U.S. strategic arms modernization plan.

The president said failure to authorize the funds "will delay the program a year and increase the cost. Thus it is essential that the House act to approve the production funds and that this action prevail in conference" with the Senate, he wrote.

Reagan wrote that he thinks "we must make a solid commitment this year to deploy the MX missile" and that "we must show our allies that we can make the hard decisions . . . . "

The president said that "while it is my intention that the MX not be a 'bargaining chip' in the START negotiations, we need to secure the powerful leverage that a commitment to produce the MX would provide as we begin" those talks.

Reagan said he wanted to "assure you that we intend to propose a final basing mode for the MX by December" and offered to "cooperate fully if the Congress wishes to place restrictions on the use of these funds until the basing decision is made in December."

In other words, Reagan was offering to comply with temporary restrictions on the funds but urging that they be authorized as what he termed "a clear signal of U.S. resolve to the Soviets."

Although the letter did not mention it, the administration has been pushing for production of MX and even a preliminary deployment in existing missile silos as a way to balance the current threat to existing U.S. Minuteman missiles by the large Soviet SS18 missiles for which there is no U.S. counterpart.

In a companion letter, Reagan urged the House to reject the Senate's insistence that the Air Force buy new or used Boeing 747 commercial airliners instead of more of the bigger C5 military jets sought by the military and already in service.

"There are no savings if what we buy will not do the job that needs to be done. Therefore, I urge you to reject the commercial aircraft proposal and support our airlift budget as submitted," the letter said.