Update: The FTSE 100 has rallied as a rebound in US markets gathered strength, with both the Dow Jones and S&P 500 opening higher.

The UK blue-chip index rose 89 points, or 1.3%, to 7,172, with bulls taking heart from a positive open for US markets following Friday's volatile session.

The Dow Jones opened 0.7% higher while the broader S&P 500 rose 1.1%, building on Friday's late rally from a fall into 'correction' territory.

'A strong open from the Dow Jones ensured that, so far at least, the week has got off to a smooth start,' said Connor Campbell, financial analyst at Spreadex.

'There is still a while to go in terms of the US session, however, and the Dow Jones has shown a predilection for savings its wider behaviour for later in the day.'

The bulk of the FTSE 100's stocks made gains in a broad-based rally, with only utilities enduring significant losses, as bond markets again showed signs of weakness, with the yield on 10-year US treasuries rising to 2.84%.

Utility companies, which tend to operate with high amounts of borrowing, are particularly vulnerable to swings in the fixed income markets.

Severn Trent (SVT) fell 1.8% to £17.89, United Utilities (UU) dropped 1% to 686.2p and SSE (SSE) traded 0.9% lower at £11.79.

The FTSE 250 was equally buoyant, up 0.9%, but shares in Acacia Mining (ACAA) were down sharply after the miner was forced to scrap its 2017 dividend due to a slump in profits sparked by a ban on unprocessed mineral exports in Tanzania.

The shares were down 4.5% at 164.3p on the news, as investors gave up hope on a speedy resolution to Acacia's dispute with the Tanzanian government, which parent company Barrick Gold is aiming to settle in the first half of this year.

'This morning's cutting of the dividend will be the final straw for many loyal shareholders who have stuck with the company in the hope a deal will be reached within the next five months, the stream of negative news finally outweighing any hope of a resolution,' said Henry Croft, research analyst at Accendo Markets.

Small cap stocks were up 0.7% but shares in UP Global Sourcing (UPGS)  crashed 47% to 32.2p after the home products supplier delivered another profit warning.

Russ Mould, investment director at AJ Bell, said the company's looming first anniversary as a listed company was providing 'little to celebrate'.

'It has issued two major profit warnings and seen its share price fall 68% in value since its 128p IPO price in March 2017,' he said.

'Although its problems are caused by external factors - namely the pace of retail orders - it does illustrate the risks of investing in small companies reliant on third parties.'