* FTSE 100 slips back below 5,000 mark
* Oils and miners under pressure
* BoE keeps rates on hold, QE maintained
By Harpreet Bhal
LONDON, Sept 10 (Reuters) - Britain's top share index slipped back in midday trade on Thursday, reversing early gains and dipping below the 5,000 mark as the market digested the Bank of England's decision to keep rates on hold at a record low.
By 1144 GMT the FTSE 100 index was down 28.29 points, or 0.6 percent at 4,976.01. It closed above the 5,000 level for the first time since late September 2008 on Wednesday.
The Bank of England left interest rates at 0.5 percent for the sixth month running and said it would keep its 175 billion pound asset buying programme in place.
Oil majors were generally lower after sharp gains in the previous session. BP, Royal Dutch Shell and Tullow Oil shed 0.5 to 1.6 percent, though BG Group rose 0.2 percent.
"You can't go up in a straight line forever so a pullback (on the FTSE) seems inevitable. The question now is, is this going to be a consolidation and a healthy pullback or is it going to be deeper," said David Morrison, market strategist at GFT Global.
The index has risen close to 44 percent since the lows of March but has struggled to breach levels hit prior to the collapse of Lehman Brothers, trading 8 percent below the event which caused chaos in the global financial system.
"The big level of a retracement from the old high to the low in March is around 5,100. That would have been technically significant. 5,000 is just psychological," Morrison said.
Mining stocks were lower, extending losses from the previous session, while gold slipped below $1,000 an ounce. Lonmin, Xstrata, Anglo American, Rio Tinto, BHP Billiton and Fresnillo fell 1.5 to 2 percent.
Food and general retailers were lower, with traders pointing to profit taking after the sectors' recent gains. The FTSE All Share General Retailers Index is up 6.1 percent so far this month, rebounding from a 0.2 percent drop in August.
Home Retail fell 6.8 percent. It reported better-than-expected second-quarter sales at both its Argos and Homebase businesses. Kingfisher, Marks & Spencer and Next dropped 3 to 4.1 percent.
Wm Morrison Supermarkets shed 2.1 percent as the food retailer said it sees slower market growth in the second half with first-half profits up 22 percent.
J Sainsbury and Tesco shed 2.4 and 1 percent, respectively.
THOMAS COOK CLIMBS
On the upside, Thomas Cook Group was in demand, adding 4 percent as Arcandor's creditor banks confirmed the placement of the German group's 43.9 percent stake in the tour operator.
The share placing was being done in an indicated range of around 240-245 pence per share, traders said.
Fellow tour operator TUI Travel rose 4.1 percent with Collins Stewart upping ratings for both to "hold" from "sell".
Defensive stocks moved higher as risk averse investors sort sanctuary in stocks which have lagged the main index rise.
Utilities Centrica, National Grid, Penon Group and United Utilities were up 0.2 to 2.1 percent
Centrica was helped by an upgrade to "buy" from Citigroup.
Drugmakers AstraZeneca and Shire gained 0.4 and 2.4 percent respectively.
On the economic front, house prices in Britain rose 0.8 percent in August, leaving prices down 10.1 percent in the three months to August versus a year ago, mortgage lender Halifax said.
British construction orders rose 2 percent in the three months to July against the previous three months, and were down 10 percent compared to a year ago, data showed.
July U.S. international trade numbers and the weekly U.S. jobless claims will be a focus at 1230 GMT. (Editing by Jon Loades-Carter)