LONDON (Reuters) - Low-cost airline easyJet (>> easyJet plc) said John Barton, chairman of British fashion retailer Next (>> NEXT plc), would become its new chairman next month, as the carrier plans to expand its fleet.

Barton, 68, who is also chairman of insurance group Catlin (>> Catlin Group Limited), will need to manage fractious relations with founder and largest shareholder Stelios Haji-Ioannou and ensure growth continues at Europe's second-largest budget airline by passengers after Ryanair (>> Ryanair Holdings plc).

"One of Barton's most important jobs will be to engage with Stelios because tensions between him and the board have been a distraction," said Espirito Santo analyst Gerald Khoo.

Stelios, whose family controls 37 percent of easyJet shares, quit the airline's board in 2010 after a row over strategy. Since then he has been critical of many of the airline's plans, including fleet expansion, executive pay and dividend policy.

Stelios, who founded the low-cost carrier in 1995, tried to oust outgoing chairman Rake last year but the attempt was rebuffed by the airline's investors.

He accused Rake of having too many corporate roles and for weak governance at UK bank Barclays (>> Barclays PLC), where he is deputy chairman. Barclays has suffered recent scandals over executive pay and an interest-rate rigging scandal.

Stelios has called on easyJet's management to slow the pace of new aircraft deliveries and focus on improving shareholder returns. He has threatened to reduce his stake in easyJet if it places a large order to expand its fleet soon.

The relationship will be tested this year if easyJet, as expected makes a large order, for new jets. EasyJet is in talks with Europe's Airbus (>> EADS) and U.S. rival Boeing (>> The Boeing Company) about a significant expansion of its fleet.

Barton, who will replace easyJet's outgoing chairman Mike Rake on May 1, has chaired Next since 2006 and has also chaired Brit Insurance, telecommunications group Cable & Wireless Worldwide and insurance broker Jardine Lloyd Thompson (>> Jardine Lloyd Thompson Group plc).

(Editing by Paul Sandle and Louise Heavens)

By Rhys Jones