Channel 4's Shackleton has become the broadcaster's most watched drama for more than 12 months, audience figures show.

Viewing figures for the two-part drama - delayed because of a change in the way the audience size is calculated - revealed that the first episode on 2 January Shackleton pulled in 3.6 million viewers

But the drama was still beaten by a screening of the film Meet Joe Black on BBC Two, with an audience of 4.3 million and a 22% audience share.

Shackleton, starring Kenneth Branagh, was Channel 4's most expensive ever programme, costing more than �10m to make.

Voyage

It charted Shackleton's doomed trans-Antartica mission.

While undertaking the voyage in 1915 Shackleton's ship became trapped in ice and the explorer had to abandon most of his crew and embark on an 800-mile trip to get help.

The second episode had an audience of 3.3 million viewers, with the same 16% share of viewing on both nights.

"Charles Sturridge's Shackleton has been Channel 4's most ambitious drama to date and our best rating commissioned drama over the last year," a Channel 4 spokesman told BBC News Online

"We are delighted that it has captured the attention of such a wide audience."

In January 2000 the adaptation of Dava Sobel's award-winning Longitude attracted 2.9m viewers.

The figures were delayed as the Broadcasters' Audience Research Board (Barb) established a new system of assessing viewing figures, which promises to be more accurate than the previous method of calculating audience size.