Aggreko rose strongly today after Citigroup reiterated its 'buy' rating on the stock.Paper and packaging group Mondi was following close behind after it delivered a 13% increase in underlying operating profits in the first quarter despite a "mixed" trading environment and flat sales volumes. Underlying operating profits totalled €183m in the three months to March 31st, up from €162m the year before and 14% ahead of the €161m reported in the fourth quarter of 2013.Also higher was catering giant Compass, which has hiked its interim dividend after a solid first half and unveiled a £1bn capital return to investors. The return, which Compass said was due to ongoing strong cash flows, is being effected by way of a special dividend and share consolidation. AstraZeneca was also in positive territory after this morning announcing a tie-up between its biologics research and development arm and biopharmaceutical company Incyte Corporation for a clinical study collaboration. Television network ITV fell sharply despite a seemingly in-line first-quarter statement with total external revenues up 2%. Analyst Steve Liechti from Investec said that the update "looks OK [with ad revenues] more or less as we expected", but "some bulls may have wanted more". The stock was down nearly 6%.A number of heavyweight stocks were trading lower after going ex-dividend, including J Sainsbury, Aberdeen Asset Management, Glencore Xstrata and Kingfisher. FTSE 100 - RisersAggreko (AGK) 1,731.00p +2.97%Mondi (MNDI) 1,051.00p +1.94%Compass Group (CPG) 998.50p +1.84%IMI (IMI) 1,585.00p +1.34%SSE (SSE) 1,528.00p +1.26%RSA Insurance Group (RSA) 489.10p +1.24%easyJet (EZJ) 1,678.00p +1.21%Experian (EXPN) 1,077.00p +1.13%G4S (GFS) 253.30p +1.12%Antofagasta (ANTO) 787.50p +1.09%FTSE 100 - FallersITV (ITV) 179.90p -5.81%Sainsbury (J) (SBRY) 326.80p -3.60%Ashtead Group (AHT) 837.50p -2.50%Barratt Developments (BDEV) 376.80p -2.46%Aberdeen Asset Management (ADN) 425.30p -2.34%ARM Holdings (ARM) 888.50p -1.99%British Sky Broadcasting Group (BSY) 842.00p -1.75%Glencore Xstrata (GLEN) 325.15p -1.66%Kingfisher (KGF) 410.60p -1.65%BG Group (BG.) 1,248.50p -1.62%NR