* Says January starts positively
* Revenue for 51 wholly owned stores rises 7 pct
* Revenue from 10 partnership stores more than doubles (Adds details)
Jan 13 (Reuters) - UK self-storage firm Big Yellow Group Plc (BYG.L) said third-quarter store revenue rose on higher occupancy and that January started positively with reservations growing in line with last year.
Big Yellow, which has 61 stores and a further nine in development, said third-quarter revenue from the 51 wholly owned stores rose 7 percent from the year-ago period to 15 million pounds ($23.64 million).
Total store revenue from 10 partnership stores more than doubled to 1.1 million pounds.
Big Yellow, whose stores are mainly in London and southeast England, said closing occupancy was 1,874,000 square feet across 51 wholly owned stores, representing 58 percent of the total capacity.
Shares of the company have risen 11.5 percent in the last six months, compared with a 20 percent rise in FTSE Mid 250 Index .FTMC. They closed at 337.60 pence on Wednesday on the London Stock Exchange. ($1=.6345 Pound) (Reporting by Purwa Naveen Raman in Bangalore; Editing by Vinu Pilakkott)