(Adds Skeoch, analyst comment, updates shares)
By Carolyn Cohn
LONDON, March 20 (Reuters) - Standard Life Chief Executive Keith Skeoch will oversee its day-to-day running after it merges with Aberdeen Asset Management, while Aberdeen boss Martin Gilbert will handle external matters like marketing, the companies said.
Analysts have expressed concern that the co-chief executive structure proposed by the firms when they announced the 11 billion-pound ($13.6 billion) merger deal two weeks ago will be unwieldy.
"Both boards have thought carefully about the key responsibilities and believe that the proposals play well to Keith’s and Martin’s respective leadership strengths," Gerry Grimstone, Standard Life chairman and chairman of the proposed firm, said in a statement on Monday.
"This blend of complementary skills and experience will serve the company well”.
Skeoch said in an emailed statement that the structure would "provide clear leadership and stability".
Skeoch's responsibilities will include investments and pensions, while Gilbert's will involve marketing and distribution, the two firms said, adding that a chairman's committee will be set up to ensure co-ordination is effective, chaired by Grimstone.
The terms of the merger valued Aberdeen at 3.8 billion pounds in a deal which gives Standard Life shareholders just over two thirds of the combined group, although the board will comprise equal numbers of Standard Life and Aberdeen directors.
Analysts say the merger is defensive, as active fund managers face increasing regulatory scrutiny and competition from lower-cost index tracking funds, and could lead to outflows from both firms.
Following an initial rally, the shares of both firms have fallen below their closing prices on March 3, shortly before the deal was announced.
Peter Lenardos, analyst at RBC, said that while the statement was helpful in soothing concerns about the co-CEO structure, "investors' primary concerns relate to ongoing net outflows at each business, and the potential for further disruption as the businesses integrate".
Lenardos has a "perform" rating on Aberdeen and "underperform" on Standard Life.
Standard Life's shares were trading at 363.4 pence at 1246 GMT, up 1 percent on the day but down 4 percent from March 3.
Aberdeen's shares were up 1.2 percent at 364 pence by 1458 GMT, when Aberdeen's shares were up 0.45 percent at 267.8 pence, valuing the company at 3.53 billion pounds. ($1 = 0.8075 pounds) (Editing by Alexander Smith, Greg Mahlich)