Teamsters and trucking industry negotiators sought the help of the government's chief mediator yesterday after the industry rejected a union wage proposal that far exceeded President Carter's anti-inflation guidelines.

Wayne L. Horvitz, chief of the Federal Mediaiton and Conciliation Service, will fly to Florida today to join the talks amid signs that tough bargaining will be required to reach a settlement by the March 31 contract deadline and avert a strike.

Horvitz, who will be accompanied by two deputies, said he expects to call a bargaining session this afternoon.

The two sides, which have not met since Teamster President Frank Fitzsimmons put the union's guidelinebusting proposal on the table last Tuesday, met for about two hours yesterday and then recessed, deferring any negotiations until Horvitz arrives.

The union's initial proposal, while expected to exceed the administration's guideline of 7 percent for wage and benefit increases, shocked both the industry and the government because of its size: more than 14 percent for wages alone in the first year and up to 50 percent for all costs over three years.

Trucking Management Inc., the industry's bargaining group, reportedly rejected the whole proposal, without bargaining a counteroffer.

Horvitz's role could be difficult. Fitzsimmons had been pressuring the administration to relax its guidelines, at least until he made his hardline bargaining demand. Whether Fitzsimmons is still interested in trying to settle within the guidelines is unclear, but Horvitz has said repeatedly his role as mediator would be undercut if he tried to negotiate for the government on guideline compliance.

Administration anti-inflation officials, noting the guidelines had been relaxed once already to accommodate Teamster benefit financing problems, rejected several Teamster proposals for exempting major cost items from its guideline calculations. This action reportedly angered Fitzsimmons, who promptly made his money proposals and cut off all communication with the administration.

However, it was reportedly the Teamsters who initially proposed mediation by Horvitz. Industry bargainers readily agreed to the proposal, making it a joint request.

Meanwhile, trucking companies began filing for rate increases with the Interstate Commerce Commission in anticipation of a new Teamster contract.

The Atlanta-based Southern Motor Carriers Rate Conference filed for a 7 percent rate increase, which its general counsel, Sherman D. Schwartzberg, said was based on an assumed annual labor cost increase of 11 to 12 percent, the amount the Teamsters got out of their current contract. The ICC, however, has served notice it will no longer automatically approve rate increases pegged to labor costs that are deemed inflationary.