The Canadian government yesterday took a conciliatory step in what has become known as the "television border war" with U.S. broadcasting interests by recommending a moratorium on its policy of deleting commercials from U.S. TV programs brought into Canada by cable.

According to Washington sources, the Canadian cabinet has recommended a "two-or three-year" halt in the Canadian Radio-Television and Telecommunications Commission (RTC) policy banning incoming commercials in Calgary, Edmonton and Toronto.

The CRTC is similar to the Federal Communications Commission here and a cabinet recommendation is viewed a binding on the CRTC, Washington sources said.

However, a controversial bill to eliminate tax deductions for Canadian advertisers putting ads aimed at the Canadian market on U.S. border stations is still due to go into effect within 12 months.

Attorneys representing the U.S border stations, particularly in Buffalo, N.Y., affected by the pending tax law change have indicated they may seek some form of U.S retaliation through the Trade Reform Act, if the Canadian government keeps the tax change in force.

American TV stations along the joint border claim that they could suffer an annual loss of $20 million in revenue if the structures on commercials remain in force.

Three Buffalo stations have formally applied to the FCC for permission to jam their own broadcasts to Canada, and a U.S. delegation traveled to Ottawa earlier this month in what turned out to be a vain effort to get the Canadian government to reconsider its position.

Yesterday's Canadian cabinet recommendation was seen as a first break in the dispute in recent years.

The FCC recently turned down a petition to deny license renewals to the Chicago networks operated TV stations sought by the Polish-American Congress on grounds of job discrimination an don the network's broad-casting of alleged "scurrilous anti-Polish jokes" on several programs.

The FCC ruled that the group had failed to substantiate its allegations regarding job exclusion.

The FCC also ruled that the First Amendment and Section 326 of the 1934 Broadcasting Act bars censorship by the commission of broadcast material.

The group had complained of jokes told on the "Mike Douglas" and "Tonight" shows, "All in the Family," "Ivan the Terrible," and portions of the Winter Olympics coverage that showed a USSR hockey team drubbing a team from Poland.

The FCC noted, however, that its decision "in no way reflects an opinion by the commission that the (Polish-American) congress is wrong as to the worth of these programs or that its members should watch them. "Rather", said the FCC, "whether a particular program merits watching is a determination best left the discretion of each viewer."

The FCC yesterday announce it was going ahead with plans for an 18-month probe of ABC, CBS and NBC to determine whether they have too much influence over the TV industry.

In a statement, the FCC said the investigation would seek to determine "whether the networks are engaging or have engaged in conduct that hampers the independent judgment of their affiliated stations or are restricting effective competition in the programming market."

The notice of inquiry was in response to complaints from the Westinghouse Broadcasting Co. (Group W) and the Justice Department.

SHORT TAKES . . . WRC's Fred Thomas is out for the week after oral surgery . . . WMAL's Barry ZeVan is in Switzerland where it's just about as cold as his current relations with anchorman David Schoumacher . . . Redskin running backs Larry Brown and Calvin Hill are among the tryouts for the "Panorama" talk show on Channel 5, where former New York mayor John Lindsay and his co-host Pat Mitchell out of Boston made a big hit this week . . . Channel 25 will carry the Senate Select Committee on Intelligence hearings on CIA director-designate Theodore Sorensen on Monday, starting at 10 a.m.