- Volumes expected to be low on half-day session- US data due out later on- Vedanta leads mining stocks lowertechMARK 2,790.20 +0.30%FTSE 100 6,750.42 +0.28%FTSE 250 15,934.64 +0.21%UK markets headed higher on Tuesday morning as investors took advantage of low volumes on a shortened trading session in London.The FTSE 100, which is due to close at 12:30 this afternoon, was up 0.3% at 6,750 in early trading. This comes after the index snapped a six-day winning streak on Monday."Trading volumes have already been extremely low over the last week or so, which is not unusual around this time of year," said Market Analyst Craig Erlam from Alpari UK. "However, with many exchanges closing early and others not opening at all, they should be even lower today."Several markets across Europe are enjoying a half day on Tuesday as traders head off early for their New Year's Eve celebrations ahead of a bank of holiday tomorrow. Germany's DAX benchmark, meanwhile, is closed for the whole day.No major economic data is due to be released Europe-side, though a raft of US indicators will keep Wall Street traders busy later on, including the S&P/Case-Shiller home-price index, Chicago PMI and consumer confidence figures."Things should pick up a lot on Thursday, and much more again next week, as traders return from their festive breaks and immerse themselves in the markets again ahead of what is likely to be a very interesting year," Erlam said.Vedanta, miners edge lowerVedanta Resources was out of favour in morning trade after saying that it has extended the employment contract of its Chief Executive Mahendra Singh Mehta by a further three months to give the board more time to find his successor.Precious metals miner Randgold Resources was among the worst performers on the FTSE 100 as gold and silver prices inched lower. FTSE 250 peers African Barrick Gold and Centamin were also unwanted.Other miners including BHP Billiton, Antofagasta, Rio Tinto and Hochschild Mining were also trading lower this morning.Monitise, the AIM-listed mobile payment technology firm, fell despite reiterating its medium-term growth prospects after saying it is seeing "continued momentum" across the group.FTSE 100 - RisersCarnival (CCL) 2,525.00p +2.10%Rexam (REX) 531.50p +1.82%Persimmon (PSN) 1,239.00p +1.72%Travis Perkins (TPK) 1,879.00p +1.68%Bunzl (BNZL) 1,458.00p +1.60%Land Securities Group (LAND) 961.00p +1.59%Marks & Spencer Group (MKS) 448.30p +1.27%Hammerson (HMSO) 501.50p +1.17%British Land Co (BLND) 627.50p +1.13%BAE Systems (BA.) 438.90p +1.13%FTSE 100 - FallersAnglo American (AAL) 1,324.50p -1.05%Coca-Cola HBC AG (CDI) (CCH) 1,729.00p -1.03%Sainsbury (J) (SBRY) 368.00p -0.84%Randgold Resources Ltd. (RRS) 3,774.00p -0.71%SSE (SSE) 1,362.00p -0.66%Weir Group (WEIR) 2,130.00p -0.65%Tullow Oil (TLW) 851.50p -0.58%Experian (EXPN) 1,111.00p -0.54%Centrica (CNA) 345.00p -0.49%Imperial Tobacco Group (IMT) 2,327.00p -0.47%FTSE 250 - RisersEssar Energy (ESSR) 75.00p +4.24%Evraz (EVR) 116.20p +4.12%Carphone Warehouse Group (CPW) 278.60p +3.30%Countrywide (CWD) 587.50p +3.16%Alent (ALNT) 358.20p +2.46%Howden Joinery Group (HWDN) 338.60p +2.05%Hays (HAS) 130.80p +2.03%Regus (RGU) 213.00p +2.01%Bank of Georgia Holdings (BGEO) 2,438.00p +1.80%Bovis Homes Group (BVS) 795.50p +1.73%FTSE 250 - FallersPayPoint (PAY) 1,026.00p -3.48%Fidessa Group (FDSA) 2,216.00p -2.98%African Barrick Gold (ABG) 183.80p -1.97%Lonmin (LMI) 305.10p -1.90%RPS Group (RPS) 343.10p -1.86%Senior (SNR) 304.50p -1.77%KCOM Group (KCOM) 98.15p -1.75%Euromoney Institutional Investor (ERM) 1,355.00p -1.67%Centamin (DI) (CEY) 44.23p -1.38%Diploma (DPLM) 690.00p -1.29%BC