Scot Caitlin McClatchey helped Great Britain's 4x400m freestyle team rewrite the British record at the World Swimming Championships in Rome.

Fran Halsall gave Britain a storming start and double Commonwealth champion McClatchey increased the advantage on her leg, clocking 54.98 seconds for her split.

Team-mates Katherine Wyld and Amy Smith hung on, despite being overtaken by the Netherlands and China, as Britain came home in 3.37.02 to advance to the final as sixth quickest.

Germany won heat three in a championship record 3.34.74 to progress as fastest.

"It's great to set a British record in the heats, it shows we are in shape and it bodes well for the rest of the week," said McClatchey.

"It's just good to get in the pool and get a feel for the venue. It's really settled me for the final and my events to come."