The FTSE Small Cap index is up 0.5 percent by midday, mirroring similar gains by both the blue chips and the mid caps, both ahead 0.6 percent.
Superglass leaps 18.4 percent, rallying after recent falls as the glass wool fibre insulation firm says in a trading update that sales in the first-half of the current financial year are significantly ahead of last year, albeit that they remain behind budgeted levels.
Thomas Cook sheds 12.4 percent, giving back some of its strong recent gains, as Investec Securities downgrades its rating for the tour operator to "hold" from "buy" on valuation grounds.
Thomas Cook's shares have risen by more than 115 percent since Investec initiated coverage on Feb. 21, but the broker says they now offer less than 10 percent upside to its unchanged 30 pence price target therefore cuts it rating.
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