The White House has run into serious opposition in Congress over President Carter's nomination of Donald L. Tucker, speaker of the Florida House of Representatives, to be vice chairman of the Civil Aeronautics Board.

A report prepared by the staff of the Senate Commerce Committee is said to have linked Tucker to a series of sizable financial deals that some panel members say are questionable.

Several persons familiar with the report likened the findings to the dealings involving President Carter's budget director, Bert Lance. One source said the panel's disclosures "make the Lance affair look tame."

Sen. Howard W. Cannon (D-Nev.), chairman of the panel's aviation subcommittee, outlined the findings in the report last Saturday to Robert J. Lipshutz, counsellor to be President, in a meeting at the White House.

Although Cannon apparently did not specifically recommend that the White House withdraw the nomination, he reportedly indicated there was substantial opposition to the appointment among both Republicans and Democrats.

While the panel has not taken any official nosecount, sources close to the committee indicatedit now as unlikely that more than a handful of the 18 senators would support the nomination.

The issue appears now to be a standstill. Senator Warren G. Magnuson (D-Wash.), chairman of the Commerce Committee, said yesterday the report was only preliminary, and the panel would continue its probe.

The White House also seems prepared to let the issue cool.One official involved in the Tucker nomination said the administration would not even consider further action until the committee completes its work.

Meanwhile, Tucker, in a telephone interview from his office in Tallahasse, denied any wrongdoing in his financial dealings, and said he did not intend to ask that his nomination be withdrawn.

"There's no reason I can see that the Senate Commerce Committee would oppose the nomination," he asserted. He said the White House had called on Monday to reassure him of the President's support.

Although both committee members and staff members refused to discuss the findings of the panel, sources confirmed the document focused in part on two instances of possible preferential treatment for Tucker on bank loans.

However, several persons familiar with the report said the document also showed "a pattern" of questionable financial dealings, which some said was similar in scope to the Lance case.

The report was distributed privately to Senators at a meeting of the committee last Friday, and then returned to the panel's safe. The full committee had been scheduled to meet yesterday, but postponed the matter indefinitely.

Possibly the most controversial item the panel is known to have investigated involves the possibly that Tucker may have received favored treatment on loans made by the Southeast First National Bank in Tallahassee.

In one case, the bank approved a $200,000 loan to a partnership that included Tucker and Richard Pelham, a Tallahassee developer, just eight days after Tucker helped push through a bill allowing branch banking in the state.

According to newspaper reports at the time, the loan previously had been rejected. Florida sources say that until the legislature approved the bill, branch banking measures had been repeately defeated.

The incident was investigated by a federal grand jury, but the panel concluded there were "no presecutable violations of federal law." Tucker denied yesterday there was any link between the loan and the banking bill.

Several directors of the Southeast Banking Coporation, the holding company which owns the bank, are officers or directors of major airlines, which would fall under Tucker's jurisdiction if he were at CAB.

A spot check yesterday showed that Harry Hood Bassett, chairman of the holding company, is a director of Eastern Airlines Frank Borman, another Southeast director, is president of Eastern. A third Southeast director, Louis J. Hector, also is on the board of National Airlines.

Another transaction being investigated by the committee involves a $350,000 loan which Southeast made to a real estate company in which Tucker had a financial interest. The firm owned a building leased in part by the state.

In that case the loan was five months overdue, but bank officials were reluctant to call it in, apparently because of Tucker's position as House speaker.

Newspaper reports at that time quoted an interoffice memorandum written by A.W. Crowely, the bank's assistant president, saying: "Because of Mr. tucker's prominence in the state legislature and his potential influence over the state agency that leases the building, legal action does not appear to be a practical solution."

Tucker denied yesterday there was any impropriety in either transaction. A disclosure statement he filed with the Commerce Committee asserts he has "no investments, liabilities, or other relations which could involve potential conflicts of interest . . ."

The unaudited statement shows as of last April 30, he had a net worth of $430,350, with assets estimated at $1.031 million and liabilities of just under $601,000.

However, he listed outstanding loans of $227,900 in short-term notes and $117,539 in long-term debts - the latter with annual interest charges totaling $15,120.

The statement also listed $70.114 in "honoria" from a Donald L. Tucker appreciation dinner, apparently a fund-raiser for a possible gubernatorial campaign in 1978.

Tucker apparently was nominated for the CAB post as something of political reward. The House speaker was candidate Carter's first prominent supporter in the critical 1976 Florida primary.

Several prominent Florida business and political leaders had pressured the White House to appoint someone from their state to serve on the CAB. The appointment won the endorsement of the State Legislature.