Eastern railroads propose to increase freight rates on 35 commodities by amounts ranging from 3 percent to 25 percent "as soon as possible," a spokesman for an eastern railroad group said yesterday.

The Traffic Executive Association Eastern Railroads has notified Western and Southern railroad groups of the prosposal and have asked them to join in the action.

Rate increases would have to be approved by the Interstate Commerce Commission. The proposal would produce about $30 million in additional revenues annually if all railroads concur.

Commodities that would bear the increased rates are the same as those that the ICC itself listed recently as needing upward rate adjustments. The ICC told the railroads that the 35 commodities weren't providing the carriers wiht enough revenue to cover the costs of handling them.

The ICC has been pressing the carriers to use more selective rate actions by commodity rather than across-the-board increases. Recently, the ICC rolled back the size of increases on seven commodities, which will reduce the railroad industry's total revenues by $50 million a year. Earlier, the commission cut the size of a proposed rate for hauling steam coal, denying the railroads a total of $56 million in revenues annually.

Under the new plan, textile waste products moving from the South to East would be increased by 25 percent. Canned and preserved fruit in 40,000-pound size shipments moving from the South to East would be increased by 20 percent.

Some of the other planned increases are citrus fruit rates, up 10 percent, fresh vegetables, up 9 percent, Eastern grain for export from Eastern ports, up 3 percent.

Meanwhile, a federal judge yesterday authorized the trustee for the Milwaukee Road to issue some $47 million in trustee certificates to rehabilitate the railroad's line from Chicago to Minneapolis-St. Paul.

U.S. District Judge Thomas R. McMillion in Chicago authorized trustee Stanley E. G. Hillman to issue the low-interest certificates which also will be used to finance new track, locomotives and cars.

The Milwaukee raod has been in financial reorganization since Dec. 19, 1977.

The largest portion, about $25.5 million, will be spent during a two-year period to improve the track at certain locations between Milwaukee and Newport, Minn., just south of St. Paul.