May 12 (Reuters) - John Menzies Plc
* Says group has had a positive start to year, continuing to make good progress against our strategic objectives.
* Says at Menzies Aviation, underlying business is performing well with solid revenue growth in period of 12 percent on a constant currency basis.
* Menzies Distribution overall sales decline of 3.1 percent in first four months of year, against year ago, is broadly in line with forecasts.
* Says rate of decline within magazine market is sharper than expected.
* Says proposed deal to combine Menzies Distribution with DX continues to move forward positively.
* Says remains confident of a conclusion to deal during summer.Source text for Eikon: Further company coverage: (Reporting By Simon Jessop)