Parts of anti-Kerry film will air

John Kerry turned against the war after serving in Vietnam

Parts of a film seen as a diatribe against US presidential candidate John Kerry will be shown on US TV on Friday.

Sinclair Broadcast Group said portions of Stolen Honor: Wounds That Never Heal would feature in a one-hour news show looking at media and elections.

Plans to show the film, which covers criticism of Mr Kerry's anti-Vietnam war activities, days ahead of the presidential vote had caused alarm.

Legal challenges were made and Sinclair shareholders voiced concerns.

Sinclair's decision has caused harm to the value of our investment in Sinclair Glickenhaus Major shareholder Excerpts from the film

Sinclair, which owns or manages 62 TV stations in the US, issued a statement saying it had never announced it would show the controversial film in its entirety.

The Stolen Honor documentary includes complaints from former US prisoners of war who allege their release was delayed after Mr Kerry's testimony to Congress in 1971 in which he denounced the war and said some soldiers committed atrocities.

Plunging shares

Democratic Party officials branded the film "blatantly partisan" and the party complained to the Federal Election Commission, arguing that any broadcast of the film should be considered as an illegal contribution to the re-election campaign of President George W Bush.

Eighteen US senators - all Democrats - complained to the Federal Communications Commission, saying it was an improper use of media networks, and the Kerry campaign applied for equal time for favourable coverage.

We are endeavouring, as we do with all of our news coverage, to present both sides of the issues covered in an equal and impartial manner Joe DeFeo, Sinclair vice-president of news

But correspondents say the key pressure came from advertisers and shareholders - the latter have seen the value of Sinclair stock drop sharply since the controversy began earlier this month.

Burger King announced it would pull all its advertising from Sinclair stations on the day of the broadcast, wishing to remain neutral in the presidential campaign.

Glickenhaus and Company, an investment firm that holds 6,100 shares of Sinclair stock, threatened legal action if Kerry supporters were not given an equal opportunity to respond to the film.

"We are not partisan. We are investors," Glickenhaus said. "Sinclair's decision has caused harm to the value of our investment in Sinclair."

Sinclair said it had tried repeatedly to get Mr Kerry or one of his representatives to take part in the news special, called A POW story: Politics, Pressure and the Media, but had not been successful.

Joe DeFeo, Sinclair's vice-president of news, said in the company statement: "As with all news programming produced by Sinclair's News Central, A POW Story is being produced with the highest journalistic standards and integrity...

"We are endeavouring, as we do with all of our news coverage, to present both sides of the issues covered in an equal and impartial manner."

Sinclair said the programme will be shown on 40 of the company's stations, which include several in states seen as key battlegrounds for the presidential election.

Earlier this week, Sinclair fired its Washington bureau chief after he publicly criticised the company's plans.