The falling pound has boosted the FTSE 100 as fresh data showed slowing growth in the UK's construction sector.
The UK blue-chip index rose 37 points, or 0.5%, to 7,319, helped by sterling's 0.4% drop against the dollar to $1,244.
A weak pound tends to support the FTSE 100, whose members rely on overseas markets for around three-quarters of their earnings.
It marks the second day in the red for sterling, which was trading as high as $1.255 before markets opened on Monday.
Signs of slowing growth in the construction sector have weighed on the pound, after the purchasing managers' index (PMI) for March dropped to 52.2, down from 52.5 in February and below the 52.4 reading that had been expected. Any reading above 50 indicates expansion.
That marks a seven-month low and follows equally disappointing data from the manufacturing sector yesterday, with a 54.2 reading down from 54.6 in February and below the 55.1 expected.
'Following yesterday's unexpected decline in manufacturing growth, today's construction PMI has also disappointed, which is another blow for the pound,' said Dennis de Jong, managing director at UFX.com.
'Sterling has been very weak over the past nine months and the data simply isn't giving the beleaguered currency any respite at present.'
A broad-based rise for the FTSE 100 saw most sectors making modest gains, but stocks with South African exposure came under renewed pressure after ratings agency Standard & Poor's (S&P) cut the country's debt rating to junk.
S&P said president Jacob Zuma's sacking of respected finance minister Pravin Gordhan represented a damaging policy shift. 'This has increased the likelihood that economic growth and fiscal outcomes could suffer,' it said.
Insurer Old Mutual (OML) and hospital group Mediclinic International (MDCM) fell to the bottom of the index, down 2.6% at 193.4p and 2.1% lower at 695.5p respectively, while on the FTSE 250, Investec (INVP) fell 1.8% to 533.5p.
Also in the red among 'mid cap' stocks was Allied Minds (ALML), down 3.9% at 260.3p in a continued sell-off on fears over the prospects for the group's portfolio of university spin-off companies and the departure of boss Chris Silva, accelerated by a last week. The shares have now fallen 37% over the last month.
Sophos (SOPH) was the biggest riser on the index, up 11.5% at 303.1p after the IT security firm said full-year results were likely to exceed expectations.
Among 'small cap' stocks, Nanoco (NANON) tumbled, down 17.4% as the nanotechnology company cut full-year expectations, saying sales had not materliased in the second half of the year.
Topps Tiles (TPT) was another heavy faller, down 7.2% at 90.8p after reporting first-half revenue of £106.5 million, down from £108 million a year ago and blaming soft market conditions in the second quarter.
Imagination Technologies (IMG) rose to the top of the index, up 8.3% as the chip maker recovered a fraction of yesterday's share price crash on news its biggest customer Apple would no longer use its products.
Asos (ASOS) was meanwhile a heavy faller on the Alternative Investment Market, down 6% at £56.19 despite the online fashion retailer posting a 37% jump in revenues, as investors took fright at higher prices eroding margins.
'The fall in the pound has boosted its international sales, however its UK margins have come under significant pressure due to heavy discounting in order to maintain market share,' said Michael Hewson, chief market analyst at CMC Markets UK.
'For a retail stock, which at the end of last week had seen gains of over 80% over the last 12 months, and despite the positive outlook, investors have decided that in the current environment a lot of the good news may well be already baked in.'