LONDON (Dow Jones)--U.K. self-storage company Big Yellow Group PLC (BYG.LN) Wednesday posted a 10% on-year increase in first-quarter revenue from its stores, and said it is cautiously encouraged by its recent performance. Chief Executive James Gibson said part of the improvement can be attributed to better trading conditions in its prime city locations. For the three months to June 30, Big Yellow said total store revenue from its 51 wholly-owned stores was GBP14.4 million--up 10% on the same quarter last year and a 5% increase from GBP13.7 million in the final quarter of its fiscal 2010. Occupancy increased by 143,000 square foot in the quarter, of which 107,000 square foot of this was in its wholly-owned stores. Big Yellow's 51 stores achieved an average net rent per square foot over the quarter of GBP26.75, which was up 4% on the same quarter last year but down 1% on the preceding quarter. Gibson added that the firm expects reasonable trading over the next few weeks before the usual seasonal slowdown from September. -By Rachael Gormley, Dow Jones Newswires; 44-20-7842-9308; [email protected] (END) Dow Jones Newswires July 07, 2010 02:35 ET (06:35 GMT)