(ShareCast News) - Vectura - which focuses on the development of pharmaceutical therapies for airways diseases - has received a letter of intent from a Skyepharma shareholder supporting the companies' proposed merger.Vectura said River and Mercantile Asset Management, which owns just under 4.8m Skyepharma shares or around 4.5%, has confirmed it will vote in favour of the merger.On Wednesday, Vectura and Skyepharma said they had reached an agreement on the terms of a recommended merger. Under the terms of the deal, Skyepharma shareholders will get 2.7977 new Vectura shares for each Skyepharma share. Based on Vectura's closing price of 146.60p on Tuesday, this values Skyepharma at 410.15p per share or around £441.13m.There will also be a partial cash alternative of up to £70m pursuant to which Skyepharma shareholders can elect to receive cash instead of some or all of the new Vectura shares to which they would otherwise be entitled under the merger.At 1150 GMT, Vectura shares were up 4.3% to 158.60p while Skyepharma was up 3.2% to 426.50p.